Frequencies for first 10,000 rows of totdiag variable in namcs1997 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      2,852       28.52       28.52
                                  1 |      3,515       35.15       63.67
                                  2 |      1,886       18.86       82.53
                                  3 |        861        8.61       91.14
                                  4 |        377        3.77       94.91
                                  5 |        190        1.90       96.81
                                  6 |        109        1.09       97.90
                                  7 |         67        0.67       98.57
                                  8 |         36        0.36       98.93
                                  9 |         34        0.34       99.27
                                 10 |         27        0.27       99.54
                                 11 |         15        0.15       99.69
                                 12 |          7        0.07       99.76
                                 13 |          2        0.02       99.78
                                 14 |          1        0.01       99.79
                                 15 |          1        0.01       99.80
                                 16 |          1        0.01       99.81
All boxes blank, including None box |         19        0.19      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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