I think itīs worth noting that immigration between 2000-2009 was actually slightly higher than it was in the decade from 1990-1999:
Green Card (LPR) Recipients 1960-1969: 3.214.000
Green Card (LPR) Recipients 1970-1979: 4.248.000
Green Card (LPR) Recipients 1980-1989: 6.244.000
Green Card (LPR) Recipients 1990-1999: 9.775.000
Green Card (LPR) Recipients 2000-2009: 10.299.000
Naturalizations 1960-1969: 1.129.000
Naturalizations 1970-1979: 1.412.000
Naturalizations 1980-1989: 2.055.000
Naturalizations 1990-1999: 4.979.000
Naturalizations 2000-2009: 6.822.000
http://www.dhs.gov/files/statistics/immigration.shtmThe US doesn`t track emigration, but if emigration remained on a level similar to 1990-1999, the population might have increased to about 315 Mio. in the 2010 Census and not to 309 like the Census Bureau estimated for April 1, 2010.
Plus: Because more people have been naturalized in this decade, the non-citizen population might remain lower at about 8%, instead of rising to about 9%. But I guess the Census count will still show a higher share of non-citizens than the American Community Survey, which had it at 7.1% in 2008, only up 1/2 of a percent from the 2000 Census.
