Externally published Church Almanac estimated in 2011 that 30% of worldwide members regularly attend church.
David G. Stewart, Jr. and Matthew Martinich, Reaching the Nations: International Church Growth Almanac (Henderson, NV: Cumorah, 2014), 11
In 2011, we estimate that approximately 30% of worldwide Latter-day Saints regularly attend church meetings and that 22% of the world's population resides in a location with an LDS congregation that they can legally attend.