xamnewt "The converse occurred after 1925 came and went without incidence. Memorial attendance dropped by three-quarters, from 88,544 in 1927 to just 17,380 in 1928. (Watchtower 1955 p.366; Yearbook 1929 p.55) (Jehovah's Witnesses in the Divine Purpose p.313) It is estimated that as many as 75% of publishers left the religion and by 1935 memorial attendance was still only 63,146.3 It took until 1940 to once again reach the same number of Watchtower followers as the pre-1925 era. "https://www.jwfacts.com/watchtower/1925.php
Sorry, my memory is faulty. The above is better.
WT 1955 p.366 "For this year of 1927 the number in attendance at the spring Memorial internationally was 88,544, yet of these only some 18,602 were active as house-to-house Kingdom announcers."
Try searching for this: W 1927, p. 302; 1929 Yearbook, p. 55.