1500, 1300, etc. etc.
https://www.labcorp.com/assets/11476
As shown above I will concede the drop from 1197 to 916 based on CDC standardization process. Hence, I use 1200 as upper limit as has been consistent for majority of RIA tests since mid 1970s.
1300, 1500, 10 000 in the old days just isn’t supported by the data we have available.