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

   rollover |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,814       68.14       68.14
          1 |      1,050       10.50       78.64
          2 |      1,469       14.69       93.33
          . |        667        6.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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