Frequencies for first 10,000 rows of rollover variable in person dataset :

   rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,787       67.87       67.87
          1 |      1,189       11.89       79.76
          2 |      1,393       13.93       93.69
          . |        631        6.31      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016