[alvin]

There is a page on BB giving an estimation. The numbers were based on observed s/n, I copy the chart here.

282 - 6212c, no suffix 10K + a block 10K + b block 10K + c block 6200+, total is around 36.2K, approximated to 40K. Obviously, no d suffix has ever been observed.

Please note, this chart has typo. e.g. 1915, to reach 100K, suffix d is not enough and suffix i is needed. I would assume that's a typo, either 100K or d suffix. Lended my books to a friend, no way to check at this moment.

..... other years, 1913, 1917, 1918 had similiar mismatching..... What did I miss here?