Frequencies for first 10,000 rows of ccs variable in namcs2007 dataset :

 does practice |
offer cervical |
        cancer |
    screening? |      Freq.     Percent        Cum.
---------------+-----------------------------------
       unknown |         30        0.30        0.30
           yes |      5,459       54.59       54.89
            no |      4,511       45.11      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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