Missouri recorded its largest decennial population growth of the 20th Century between 1990 and 2000 – an increase of 9.3 percent resulting primarily from migration. State Demographer Ryan Burson estimates 286,000 people moved into Missouri during the decade of the 1990s, compared to a net gain of 210,000 due to births and deaths. The co-called millennium boom exceeds the growth that was seen during the Baby Boom decade of the 1950s, which saw 9.2 percent statewide growth.