Frequencies for first 10,000 rows of amb23 variable in nhamcsopd2000 dataset :

 ambulatory |
       surg |
  procedure |
 #2 - 3 dgt |      Freq.     Percent        Cum.
------------+-----------------------------------
        000 |      9,952       99.52       99.52
        033 |          1        0.01       99.53
        039 |          1        0.01       99.54
        137 |          1        0.01       99.55
        218 |          1        0.01       99.56
        429 |          1        0.01       99.57
        452 |          1        0.01       99.58
        490 |          1        0.01       99.59
        511 |          1        0.01       99.60
        573 |          2        0.02       99.62
        663 |          1        0.01       99.63
        671 |          1        0.01       99.64
        672 |          1        0.01       99.65
        690 |          1        0.01       99.66
        702 |          1        0.01       99.67
        753 |          3        0.03       99.70
        756 |          1        0.01       99.71
        770 |          1        0.01       99.72
        793 |          1        0.01       99.73
        808 |          1        0.01       99.74
        860 |          1        0.01       99.75
        861 |          2        0.02       99.77
        862 |          1        0.01       99.78
        863 |          5        0.05       99.83
        865 |          2        0.02       99.85
        866 |          2        0.02       99.87
        883 |          2        0.02       99.89
        891 |          1        0.01       99.90
        933 |          1        0.01       99.91
        935 |          3        0.03       99.94
        965 |          2        0.02       99.96
        973 |          2        0.02       99.98
        999 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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