The Census estimate for the US for 2009 was less than the Count for 2010

The estimate, at 307,006,550, was .6 percent less than the count of 308,745,538.  Yet for the ten largest cities, the estimate was 4 percent higher than the count.  Again, it would be nice no know whether cities were overestimated in 2009 or undercounted in 2010.