Frequencies for first 10,000 rows of chow_cnt variable in posclia2011 dataset :

   CHOW_CNT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,960       99.60       99.60
          1 |         17        0.17       99.77
          2 |         20        0.20       99.97
          3 |          2        0.02       99.99
          4 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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