Frequencies for first 10,000 rows of spec variable in namcs2002 dataset :

  Physician |
  specialty |      Freq.     Percent        Cum.
------------+-----------------------------------
         AI |         38        0.38        0.38
         CD |        534        5.34        5.72
        CHP |        112        1.12        6.84
        CRS |         35        0.35        7.19
          D |        665        6.65       13.84
         EM |         42        0.42       14.26
        END |         38        0.38       14.64
         FP |      1,667       16.67       31.31
        FPS |         57        0.57       31.88
         GE |        179        1.79       33.67
         GP |        229        2.29       35.96
         GS |        463        4.63       40.59
        GYN |         42        0.42       41.01
         HS |         34        0.34       41.35
         ID |          3        0.03       41.38
         IM |        848        8.48       49.86
        MFM |         14        0.14       50.00
        MPD |         20        0.20       50.20
          N |        494        4.94       55.14
        NEP |         38        0.38       55.52
         NS |          6        0.06       55.58
        OBG |        460        4.60       60.18
         OM |         29        0.29       60.47
         ON |         45        0.45       60.92
        OPH |        564        5.64       66.56
        ORS |        493        4.93       71.49
         OS |         37        0.37       71.86
        OTO |        551        5.51       77.37
          P |        359        3.59       80.96
         PD |        980        9.80       90.76
         PG |         16        0.16       90.92
         PM |         97        0.97       91.89
         PN |         34        0.34       92.23
         PS |         28        0.28       92.51
        PUD |         40        0.40       92.91
        PYG |          8        0.08       92.99
        RHU |         24        0.24       93.23
         TS |         18        0.18       93.41
          U |        579        5.79       99.20
         UP |         61        0.61       99.81
         VS |         19        0.19      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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