New estimates of San Diego County’s population show it peaking at 3.4 million in about 20 years, followed by a drop off.

The San Diego Association of Governments says the county will add 152,075 people by 2042, and then start dropping. It estimates the population will drop to 3.3 million by 2060, or pretty close to what it is right now, making it one of the slowest growing metro areas in the U.S.