Frequencies for first 10,000 rows of prov2615 variable in pos1994 dataset :

   calendar |
  year test |
     volume |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,463       94.63       94.63
         90 |        292        2.92       97.55
         91 |        245        2.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017