Frequencies for first 10,000 rows of ordperf1 variable in nhamcsopd2003 dataset :

  surg procedure #1 - |
   ord/sched or perf? |      Freq.     Percent        Cum.
----------------------+-----------------------------------
                blank |      8,747       87.47       87.47
    ordered/scheduled |        457        4.57       92.04
            performed |        592        5.92       97.96
ordered and performed |        132        1.32       99.28
              unknown |         72        0.72      100.00
----------------------+-----------------------------------
                Total |     10,000      100.00

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