Frequencies for first 10,000 rows of vyear variable in nhamcsed1992 dataset :

    Year of |
  visit - 2 |
     digits |      Freq.     Percent        Cum.
------------+-----------------------------------
         91 |      1,007       10.07       10.07
         92 |      8,993       89.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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