Frequencies for first 10,000 rows of ordperf1 variable in nhamcsopd2004 dataset :

  surg procedure #1 - |
   ord/sched or perf? |      Freq.     Percent        Cum.
----------------------+-----------------------------------
                blank |      9,329       93.29       93.29
    ordered/scheduled |        221        2.21       95.50
            performed |        329        3.29       98.79
ordered and performed |         54        0.54       99.33
              unknown |         67        0.67      100.00
----------------------+-----------------------------------
                Total |     10,000      100.00

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