Frequencies for first 10,000 rows of bdatefl variable in nhamcsed2001 dataset :

was patient |
 birth year |
   imputed? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,724       97.24       97.24
          1 |        276        2.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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