How many Contax N-mount lenses were made?

lensest#1est#2
100/2.830692919
17-3520452026
24-851908317336
28-80982810919
400/4516502
50/1.462945737
70-200103258986
70-30099588529
85/1.415661484
Total6268458438
We record serial numbers of lenses we have worked on, and estimate the total number of lenses manufactured using statistical techniques.

Estimate 1 is simply the difference between the smallest and the largest serial number we have on record.

Estimate 2 assumes serial numbers form a rectangular distribution. This would only work if we have a sufficient sample size (sometimes we don't), and if the serial numbers are consecutive, with no gaps in between. So, take our estimates with a grain of salt.