Frequencies for first 10,000 rows of year variable in usstate19ageswhnonwhoriginadj dataset :

       Year |      Freq.     Percent        Cum.
------------+-----------------------------------
       1981 |      7,752       77.52       77.52
       1982 |      2,248       22.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 2 Jan 2016