Factor 8 and Factor 9 were made at the Plasma Fractionation Laboratory in Oxford. The number of donations in the mean pool size for Factor 8 in 1969 was 160 donations; in 1970 it was 192 and the same in 1971. In terms of Factor 9, larger pools were used: in 1969, 439 donations were the average, in 1970 it was 384, and in 1971, 300.