Frequencies for first 10,000 rows of sigprov variable in namcs2015 dataset :

Sigmoidosco |
py provided |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |          5        0.05        0.05
         -7 |      9,946       99.46       99.51
          1 |         48        0.48       99.99
          2 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 25 Oct 2017