Frequencies for first 10,000 rows of prov4175 variable in posclia2009 dataset :

   multiple |
       site |
certificate |
        ind |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,593       95.93       95.93
          Y |        407        4.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016