Frequencies for first 10,000 rows of nationalpdp variable in ma2008 dataset :

   National |
        PDP |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,802       98.02       98.02
          Y |        198        1.98      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 14 Apr 2016