Frequencies for first 10,000 rows of amb variable in nhamcsopd2001 dataset :

    were surgical |
       procedures |
     ord/sched or |
            perf? |      Freq.     Percent        Cum.
------------------+-----------------------------------
               No |      9,306       93.06       93.06
              Yes |        694        6.94      100.00
------------------+-----------------------------------
            Total |     10,000      100.00

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