Frequencies for year variable in namcsphys2005_2010 dataset :

survey year |      Freq.     Percent        Cum.
------------+-----------------------------------
       2005 |      1,058       14.20       14.20
       2006 |      1,268       17.02       31.23
       2007 |      1,357       18.22       49.44
       2008 |      1,187       15.94       65.38
       2009 |      1,291       17.33       82.71
       2010 |      1,288       17.29      100.00
------------+-----------------------------------
      Total |      7,449      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016