Frequencies for first 10,000 rows of paydk variable in namcs2010 dataset :

    unknown |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,695       96.95       96.95
        yes |        305        3.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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