being of mixed European ancestries (measuring 'blood' in modern parlance akin to DNA test results measuring an individual's ancestral makeup, applied to a population.) Quota calculation formula The national origins formula prescribed by the Immigration Act of 1924, effective 1929, capped total annual quota immigration from outside the Western Hemisphere at 150,000. The quota for each country was to be computed as a fraction of 150,000 in a ratio proportional to the number of U.S. inhabitants of each national origin as a share of total inhabitants in 1920, with a minimum quota of 100. Due to the minimum rounding up the quotas for all countries that would not have otherwise reached 100, in practice the annual global quota total was slightly more than 150,000 (in 1930 totaling 153,714), but the formula calculation still used the fixed number 150,000. The total number of U.S. inhabitants in 1920 with national origins in quota countries was 89,506,558 so the national origins formula f expressed mathematically as , where n is the number of inhabitants of any given national origin and q is the quota, hence to convert n into q required multiplication of n by . For example, the number of U.S. inhabitants in 1920 who were derived from the United Kingdom was fixed at 39,216,333 so the formula . The formula could thus be solved for q as: . Or the formula could be solved to compute the quota by converting the fraction for the national origin into decimal form, then multiplying to take the equivalent percentage share of 150,000: . The table below lists the number of U.S. inhabitants of each national origin in 1920, and their fractional share of the total quota population expressed in percentage form to three decimal points. The revised national origins formula prescribed by the Immigration and Nationality Act of 1952, effective 1953, was simplified to multiply n by of 1% (equivalent to decimal 0.00166666666̅) to arrive at roughly equivalent (but slightly reduced) quotas by a much streamlined process e.g. . Under the Immigration and Nationality Act of 1965, quotas were temporarily retained, but all unused quota spots each year were pooled and made available to other countries effective December 1, 1965. The National Origins Formula fully ended on July 1, 1968, replaced by simple broad numerical limitations of 120,000 from the Western Hemisphere and 170,000 from the Eastern Hemisphere, with no more than 20,000 from