The obvious culprit is SB 656.
But I think there are two other major explanations:
(1) Law of diminishing marginal returns. The rate of permit applications and issuance over the past several years was so brisk that, eventually, we were going to reach a point where anyone who remotely entertained the idea of wanting a permit already has one.
(2) OCGE. He replaced the World’s Greatest Firearms Salesman. That has the firearms industry in the dumper, and that has probably also contributed to the slowdown in applications for carry permits.
One way to test these three theories is to check other states’ pace of permit applications.