Frequencies for first 10,000 rows of spec variable in namcs2001 dataset :

  physician |
  specialty |      Freq.     Percent        Cum.
------------+-----------------------------------
         AI |         35        0.35        0.35
         CD |        509        5.09        5.44
        CHN |         43        0.43        5.87
        CHP |        149        1.49        7.36
          D |        944        9.44       16.80
         FP |      1,160       11.60       28.40
         GE |        190        1.90       30.30
         GP |        133        1.33       31.63
         GS |        465        4.65       36.28
        GYN |         90        0.90       37.18
         HS |         39        0.39       37.57
         ID |          4        0.04       37.61
         IM |        578        5.78       43.39
        IMG |         36        0.36       43.75
        MPD |         57        0.57       44.32
          N |        563        5.63       49.95
        NEP |         13        0.13       50.08
         NS |         53        0.53       50.61
        OBG |        581        5.81       56.42
         ON |         47        0.47       56.89
         OP |         24        0.24       57.13
        OPH |        510        5.10       62.23
        ORS |        733        7.33       69.56
        OSM |         31        0.31       69.87
        OSS |         18        0.18       70.05
        OTO |        565        5.65       75.70
          P |        547        5.47       81.17
        PCC |         22        0.22       81.39
         PD |        841        8.41       89.80
        PHP |         29        0.29       90.09
         PM |         37        0.37       90.46
         PS |         39        0.39       90.85
        PUD |         76        0.76       91.61
        PYG |         23        0.23       91.84
        RHU |         26        0.26       92.10
          U |        726        7.26       99.36
         UP |         22        0.22       99.58
         VS |         42        0.42      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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