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

Share lab results |
   electronically |
  (not fax) with: |
          unknown |      Freq.     Percent        Cum.
------------------+-----------------------------------
   Not applicable |      6,561       65.61       65.61
Box is not marked |      3,399       33.99       99.60
    Box is marked |         40        0.40      100.00
------------------+-----------------------------------
            Total |     10,000      100.00

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