Frequencies for first 10,000 rows of amb12 variable in namcs1998 dataset :

 ambulatory |
       surg |
  procedure |
 #1 - 2 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
         00 |      9,726       97.26       97.26
         03 |          1        0.01       97.27
         04 |          1        0.01       97.28
         06 |          2        0.02       97.30
         12 |          1        0.01       97.31
         18 |          2        0.02       97.33
         21 |          2        0.02       97.35
         25 |          1        0.01       97.36
         31 |          1        0.01       97.37
         34 |          1        0.01       97.38
         38 |          1        0.01       97.39
         39 |          9        0.09       97.48
         40 |          1        0.01       97.49
         45 |          8        0.08       97.57
         48 |          4        0.04       97.61
         49 |          3        0.03       97.64
         51 |          3        0.03       97.67
         53 |          6        0.06       97.73
         54 |          1        0.01       97.74
         55 |          1        0.01       97.75
         57 |          6        0.06       97.81
         64 |          2        0.02       97.83
         67 |          1        0.01       97.84
         68 |          1        0.01       97.85
         69 |          3        0.03       97.88
         70 |          4        0.04       97.92
         71 |          2        0.02       97.94
         81 |          6        0.06       98.00
         83 |          2        0.02       98.02
         85 |         13        0.13       98.15
         86 |        135        1.35       99.50
         89 |          3        0.03       99.53
         93 |          5        0.05       99.58
         94 |          1        0.01       99.59
         96 |         13        0.13       99.72
         97 |         20        0.20       99.92
         98 |          2        0.02       99.94
         99 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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