Frequencies for first 10,000 rows of amb22 variable in nhamcsopd2000 dataset :

 ambulatory |
       surg |
  procedure |
 #2 - 2 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      9,952       99.52       99.52
         03 |          2        0.02       99.54
         13 |          1        0.01       99.55
         21 |          1        0.01       99.56
         42 |          1        0.01       99.57
         45 |          1        0.01       99.58
         49 |          1        0.01       99.59
         51 |          1        0.01       99.60
         57 |          2        0.02       99.62
         66 |          1        0.01       99.63
         67 |          2        0.02       99.65
         69 |          1        0.01       99.66
         70 |          1        0.01       99.67
         75 |          4        0.04       99.71
         77 |          1        0.01       99.72
         79 |          1        0.01       99.73
         80 |          1        0.01       99.74
         86 |         13        0.13       99.87
         88 |          2        0.02       99.89
         89 |          1        0.01       99.90
         93 |          4        0.04       99.94
         96 |          2        0.02       99.96
         97 |          2        0.02       99.98
         99 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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