Frequencies for first 10,000 rows of vyear2 variable in nhamcsed1995 dataset :

    year of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
         94 |        207        2.07        2.07
         95 |      9,793       97.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016