Excellent Covert Shores Article on Soviet/Russian Submarine Activity

H I Sutton at Covert Shores regularly publishes interesting articles on submarines. For example:

Increase in #Russian Submarine Activity of 22 May 2018 http://www.hisutton.com/Russian_Submarine_Activity.html

"There have been reports that Russian submarine activity has returned to Cold War levels. This article uses publicly available data to compare recent activity to Cold War levels...." See WHOLE CORVERT SHORES ARTICLE

A useful Table courtesy Covert Shores. It indicates the steep decline in Russian submarine numbers since the Cold War years (1947-1991) with over 400 Russian subs in some years) to many less than 100 since 1991 (eg. 66 in 2016). 

What trends do you see in the Table (eg. more than 200 SSKs in 1980)?