Frequencies for first 10,000 rows of totdiag variable in namcs1998 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      3,361       33.61       33.61
                                  1 |      3,386       33.86       67.47
                                  2 |      1,649       16.49       83.96
                                  3 |        712        7.12       91.08
                                  4 |        330        3.30       94.38
                                  5 |        220        2.20       96.58
                                  6 |        109        1.09       97.67
                                  7 |         78        0.78       98.45
                                  8 |         54        0.54       98.99
                                  9 |         38        0.38       99.37
                                 10 |         28        0.28       99.65
                                 11 |         14        0.14       99.79
                                 12 |         15        0.15       99.94
                                 13 |          3        0.03       99.97
                                 14 |          2        0.02       99.99
                                 15 |          1        0.01      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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