Frequencies for first 10,000 rows of bioprov variable in namcs2012 dataset :

        Biopsy |
      provided |      Freq.     Percent        Cum.
---------------+-----------------------------------
         Blank |         27        0.27        0.27
Not applicable |      9,840       98.40       98.67
           Yes |         97        0.97       99.64
            No |         36        0.36      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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