Frequencies for first 10,000 rows of amb22 variable in nhamcsopd1999 dataset :

 ambulatory |
       surg |
  procedure |
 #2 - 2 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      9,908       99.08       99.08
         03 |          1        0.01       99.09
         08 |          1        0.01       99.10
         21 |          1        0.01       99.11
         30 |          1        0.01       99.12
         34 |          1        0.01       99.13
         39 |          2        0.02       99.15
         40 |          3        0.03       99.18
         42 |          7        0.07       99.25
         44 |          1        0.01       99.26
         45 |         23        0.23       99.49
         54 |          1        0.01       99.50
         56 |          3        0.03       99.53
         57 |          4        0.04       99.57
         59 |          1        0.01       99.58
         65 |          1        0.01       99.59
         67 |          1        0.01       99.60
         69 |          3        0.03       99.63
         80 |         11        0.11       99.74
         81 |          1        0.01       99.75
         82 |          1        0.01       99.76
         85 |          3        0.03       99.79
         86 |         10        0.10       99.89
         87 |          1        0.01       99.90
         88 |          1        0.01       99.91
         93 |          2        0.02       99.93
         96 |          4        0.04       99.97
         98 |          1        0.01       99.98
         99 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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