Underattendance

[…] any honest student of conditions in rural churches is confronted by staggering and depressing statistics of overchurching and underattendance in some sections, and of entire lack of attendance due to no churching at all in others.

Source: wiktionary

The underattendance of boys at high schools was a cause of regular lament by all, including girl students who were left without escorts after school social functions.

Source: wiktionary