Frequencies for first 10,000 rows of totdiag variable in namcs1999 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      3,115       31.15       31.15
                                  1 |      3,593       35.93       67.08
                                  2 |      1,744       17.44       84.52
                                  3 |        793        7.93       92.45
                                  4 |        344        3.44       95.89
                                  5 |        197        1.97       97.86
                                  6 |         93        0.93       98.79
                                  7 |         46        0.46       99.25
                                  8 |         28        0.28       99.53
                                  9 |         17        0.17       99.70
                                 10 |         14        0.14       99.84
                                 11 |          9        0.09       99.93
                                 12 |          5        0.05       99.98
                                 13 |          1        0.01       99.99
                                 14 |          1        0.01      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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