Frequencies for first 10,000 rows of vyear variable in nhamcsopd1994 dataset :

    year of |
    visit - |
     last 2 |
     digits |      Freq.     Percent        Cum.
------------+-----------------------------------
         93 |         79        0.79        0.79
         94 |      9,921       99.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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