Frequencies for first 10,000 rows of vyear variable in namcs2002 dataset :

    Year of |
      visit |      Freq.     Percent        Cum.
------------+-----------------------------------
       2002 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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