Frequencies for first 10,000 rows of scpwi22d variable in nhamcsopd2007 dataset :

scope write |
  in #2 - 2 |
      digit |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      9,986       99.86       99.86
         21 |          1        0.01       99.87
         44 |          1        0.01       99.88
         45 |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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