Frequencies for first 10,000 rows of year variable in nhamcsopd2001 dataset :

survey year |
       2001 |      Freq.     Percent        Cum.
------------+-----------------------------------
       2001 |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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