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

   hospital |
clinic code |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      3,164       31.64       31.64
          2 |      1,867       18.67       50.31
          3 |      1,583       15.83       66.14
          4 |      1,314       13.14       79.28
          5 |      1,069       10.69       89.97
          6 |        177        1.77       91.74
          7 |        220        2.20       93.94
          8 |        196        1.96       95.90
          9 |         92        0.92       96.82
         10 |         74        0.74       97.56
         11 |         35        0.35       97.91
         12 |         49        0.49       98.40
         13 |         70        0.70       99.10
         14 |         33        0.33       99.43
         21 |         33        0.33       99.76
         22 |         24        0.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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