There were 4.2% fewer births in the United States 2009 than there were at the 2007 peak. In Colorado, there were 3.2% fewer births.
The trends don't necessary closely track the impact of the financial crisis. Florida and Nevada, for example, were both very hard hit economically, but did not see big declines in births (Florida's increased, Nevada's stayed almost the same). But, births are, of course, a lagging indicator of economic conditions and this may simply reflect differences in when different states felt the impact of an economic downturn.
Colorado beat a national trend towards fewer marriages (there were about 7% fewer in 2009 than 2007 nationwide). There were 9.6% more marriages in Colorado in 2009 than there were in 2007. The number of divorces in Colorado, in contrast, rose only 0.1% from 2007 to 2009. So many states have ceased reporting divorce information to national statistical officials that national divorce rate figures are no longer meaningful.
The U.S. population grew about 1.5% from 2007 to 2009.