My block: virtually all white

This is very strange for San Francisco. My sister just looked up the census data on race for my block in Noe Valley in the year 2000:

Total: 124 (100%)

Population of one race:
White alone: 108 (87.1%)
Black or African American alone: 0 (0%)
American Indian and Alaska Native alone: 0 (0%)
Asian alone: 6 (0.05%)
Some other race alone: 3 (0.024%)

Population of two races:
White/Black or African American: 1 (0.008%)
White/Asian: 2 (0.016%)
White/Some other race: 3 (0.024%)

Population of three races:
White/Asian/Native Hawaiian and Other Pacific Islander: 1 (0.008%)

Things have probably changed since then (for example, the addition of my household and my neighbor's household adds FOUR Asian folk to the block), but it's still weird.