Contra Costa County Historical First Ancestry Data
ACS 2010-2014 data
982,928 (90.91%) out of the total population of 1,081,232 reported first ancestry.
| Contra Costa County | % of the Total Population | California | U.S. | |
| Arab | 8,093 | 0.75%, see rank | 0.72% | 0.56% |
| Czech | 2,783 | 0.26%, see rank | 0.22% | 0.47% |
| Danish | 7,461 | 0.69%, see rank | 0.46% | 0.42% |
| Dutch | 11,401 | 1.05%, see rank | 0.99% | 1.40% |
| English | 81,560 | 7.54%, see rank | 5.94% | 8.02% |
| French | 26,755 | 2.47%, see rank | 2.15% | 3.34% |
| German | 106,574 | 9.86%, see rank | 8.51% | 15.03% |
| Greek | 5,413 | 0.50%, see rank | 0.35% | 0.41% |
| Hungarian | 3,694 | 0.34%, see rank | 0.32% | 0.46% |
| Irish | 95,890 | 8.87%, see rank | 6.69% | 10.80% |
| Italian | 65,838 | 6.09%, see rank | 3.97% | 5.52% |
| Norwegian | 15,588 | 1.44%, see rank | 1.02% | 1.42% |
| Polish | 14,076 | 1.30%, see rank | 1.32% | 3.01% |
| Portuguese | 19,621 | 1.81%, see rank | 0.91% | 0.44% |
| Russian | 13,977 | 1.29%, see rank | 1.13% | 0.92% |
| Scotch-Irish | 7,774 | 0.72%, see rank | 0.61% | 0.99% |
| Scottish | 18,564 | 1.72%, see rank | 1.34% | 1.72% |
| Subsaharan African | 9,690 | 0.90%, see rank | 0.69% | 0.95% |
| Swedish | 14,912 | 1.38%, see rank | 1.09% | 1.27% |
| Swiss | 3,534 | 0.33%, see rank | 0.27% | 0.30% |
| Ukrainian | 3,211 | 0.30%, see rank | 0.27% | 0.31% |
| American | 36,980 | 3.42%, see rank | 3.22% | 7.12% |
| Welsh | 5,082 | 0.47%, see rank | 0.43% | 0.57% |
ACS 2008-2012 data
976,682 (92.84%) out of the total population of 1,052,047 reported first ancestry.
| Contra Costa County | % of the Total Population | California | U.S. | |
| Arab | 7,465 | 0.71%, see rank | 0.70% | 0.53% |
| Czech | 2,866 | 0.27%, see rank | 0.24% | 0.50% |
| Danish | 7,624 | 0.72%, see rank | 0.50% | 0.45% |
| Dutch | 11,987 | 1.14%, see rank | 1.08% | 1.51% |
| English | 83,456 | 7.93%, see rank | 6.39% | 8.53% |
| French | 26,155 | 2.49%, see rank | 2.28% | 3.54% |
| German | 109,640 | 10.42%, see rank | 9.10% | 15.79% |
| Greek | 5,930 | 0.56%, see rank | 0.35% | 0.42% |
| Hungarian | 4,014 | 0.38%, see rank | 0.34% | 0.48% |
| Irish | 95,986 | 9.12%, see rank | 7.13% | 11.36% |
| Italian | 63,555 | 6.04%, see rank | 4.08% | 5.66% |
| Norwegian | 15,733 | 1.50%, see rank | 1.06% | 1.46% |
| Polish | 14,511 | 1.38%, see rank | 1.35% | 3.13% |
| Portuguese | 19,656 | 1.87%, see rank | 0.96% | 0.46% |
| Russian | 14,063 | 1.34%, see rank | 1.18% | 0.97% |
| Scotch-Irish | 7,961 | 0.76%, see rank | 0.67% | 1.07% |
| Scottish | 19,151 | 1.82%, see rank | 1.43% | 1.81% |
| Subsaharan African | 10,538 | 1.00%, see rank | 0.72% | 0.93% |
| Swedish | 15,165 | 1.44%, see rank | 1.16% | 1.34% |
| Swiss | 3,614 | 0.34%, see rank | 0.28% | 0.31% |
| Ukrainian | 3,417 | 0.32%, see rank | 0.26% | 0.31% |
| American | 33,957 | 3.23%, see rank | 2.78% | 6.72% |
| Welsh | 6,831 | 0.65%, see rank | 0.46% | 0.60% |
ACS 2006-2010 data
959,903 (93.67%) out of the total population of 1,024,809 reported first ancestry.
| Contra Costa County | % of the Total Population | California | U.S. | |
| Arab | 6,803 | 0.66%, see rank | 0.66% | 0.50% |
| Czech | 3,368 | 0.33%, see rank | 0.26% | 0.53% |
| Danish | 7,841 | 0.77%, see rank | 0.53% | 0.48% |
| Dutch | 13,682 | 1.34%, see rank | 1.15% | 1.63% |
| English | 89,726 | 8.76%, see rank | 6.77% | 9.02% |
| French | 29,958 | 2.92%, see rank | 2.44% | 3.77% |
| German | 119,456 | 11.66%, see rank | 9.60% | 16.51% |
| Greek | 5,414 | 0.53%, see rank | 0.38% | 0.44% |
| Hungarian | 4,201 | 0.41%, see rank | 0.36% | 0.51% |
| Irish | 100,252 | 9.78%, see rank | 7.50% | 11.76% |
| Italian | 62,794 | 6.13%, see rank | 4.21% | 5.78% |
| Norwegian | 15,334 | 1.50%, see rank | 1.10% | 1.51% |
| Polish | 15,430 | 1.51%, see rank | 1.41% | 3.24% |
| Portuguese | 22,363 | 2.18%, see rank | 1.02% | 0.47% |
| Russian | 13,869 | 1.35%, see rank | 1.22% | 1.01% |
| Scotch-Irish | 15,795 | 1.54%, see rank | 1.19% | 1.72% |
| Scottish | 21,135 | 2.06%, see rank | 1.54% | 1.92% |
| Subsaharan African | 15,309 | 1.49%, see rank | 0.72% | 0.91% |
| Swedish | 16,741 | 1.63%, see rank | 1.25% | 1.41% |
| Swiss | 4,083 | 0.40%, see rank | 0.31% | 0.33% |
| Ukrainian | 2,994 | 0.29%, see rank | 0.26% | 0.31% |
| American | 24,136 | 2.36%, see rank | 2.43% | 6.28% |
| Welsh | 6,915 | 0.67%, see rank | 0.49% | 0.63% |
ACS 2005-2009 data
952,549 (93.79%) out of the total population of 1,015,571 reported first ancestry.
| Contra Costa County | % of the Total Population | California | U.S. | |
| Arab | 6,705 | 0.66%, see rank | 0.66% | 0.50% |
| Czech | 3,392 | 0.33%, see rank | 0.27% | 0.54% |
| Danish | 7,391 | 0.73%, see rank | 0.55% | 0.49% |
| Dutch | 14,191 | 1.40%, see rank | 1.19% | 1.68% |
| English | 92,289 | 9.09%, see rank | 7.02% | 9.29% |
| French | 31,401 | 3.09%, see rank | 2.56% | 3.90% |
| German | 124,098 | 12.22%, see rank | 9.93% | 16.89% |
| Greek | 5,902 | 0.58%, see rank | 0.38% | 0.45% |
| Hungarian | 4,476 | 0.44%, see rank | 0.37% | 0.52% |
| Irish | 101,574 | 10.00%, see rank | 7.79% | 12.01% |
| Italian | 64,554 | 6.36%, see rank | 4.33% | 5.91% |
| Norwegian | 15,789 | 1.55%, see rank | 1.14% | 1.55% |
| Polish | 16,722 | 1.65%, see rank | 1.45% | 3.32% |
| Portuguese | 20,490 | 2.02%, see rank | 1.05% | 0.48% |
| Russian | 14,386 | 1.42%, see rank | 1.25% | 1.04% |
| Scotch-Irish | 15,980 | 1.57%, see rank | 1.23% | 1.77% |
| Scottish | 20,738 | 2.04%, see rank | 1.61% | 1.97% |
| Subsaharan African | 15,986 | 1.57%, see rank | 0.71% | 0.88% |
| Swedish | 17,503 | 1.72%, see rank | 1.28% | 1.45% |
| Swiss | 4,130 | 0.41%, see rank | 0.32% | 0.34% |
| Ukrainian | 2,898 | 0.29%, see rank | 0.27% | 0.32% |
| American | 23,399 | 2.30%, see rank | 2.66% | 6.43% |
| Welsh | 7,956 | 0.78%, see rank | 0.52% | 0.65% |
US Census 2000 data
824,440 (86.89%) out of the total population of 948,816 reported first ancestry.
| Contra Costa County | % of the Total Population | California | U.S. | |
| Arab | 4,285 | 0.45%, see rank | 0.50% | 0.36% |
| Czech | 1,381 | 0.15%, see rank | 0.14% | 0.27% |
| Danish | 5,764 | 0.61%, see rank | 0.38% | 0.30% |
| Dutch | 8,122 | 0.86%, see rank | 0.71% | 0.91% |
| English | 60,456 | 6.37%, see rank | 4.91% | 5.91% |
| French | 17,011 | 1.79%, see rank | 1.57% | 2.39% |
| German | 74,048 | 7.80%, see rank | 6.45% | 10.81% |
| Greek | 3,876 | 0.41%, see rank | 0.29% | 0.34% |
| Hungarian | 2,512 | 0.26%, see rank | 0.27% | 0.32% |
| Irish | 63,694 | 6.71%, see rank | 4.72% | 6.85% |
| Italian | 53,527 | 5.64%, see rank | 3.41% | 4.59% |
| Norwegian | 12,126 | 1.28%, see rank | 0.92% | 1.15% |
| Polish | 11,373 | 1.20%, see rank | 0.95% | 2.24% |
| Portuguese | 13,574 | 1.43%, see rank | 0.75% | 0.33% |
| Russian | 8,792 | 0.93%, see rank | 0.90% | 0.68% |
| Scotch-Irish | 10,656 | 1.12%, see rank | 0.87% | 1.17% |
| Scottish | 13,223 | 1.39%, see rank | 1.00% | 1.12% |
| Subsaharan African | 7,139 | 0.75%, see rank | 0.51% | 0.61% |
| Swedish | 11,952 | 1.26%, see rank | 0.86% | 0.87% |
| Swiss | 2,741 | 0.29%, see rank | 0.21% | 0.19% |
| Ukrainian | 1,696 | 0.18%, see rank | 0.20% | 0.24% |
| American | 29,625 | 3.12%, see rank | 3.37% | 7.33% |
| Welsh | 3,513 | 0.37%, see rank | 0.27% | 0.31% |
* ACS stands for U.S. Census American Community Survey. According to the U.S. Census, if the date is a range, you can interpret the data as an average of the period of time.