Frequencies for first 10,000 rows of totdiag variable in nhamcsopd1997 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      2,573       25.73       25.73
                                  1 |      3,120       31.20       56.93
                                  2 |      2,039       20.39       77.32
                                  3 |        969        9.69       87.01
                                  4 |        543        5.43       92.44
                                  5 |        293        2.93       95.37
                                  6 |        207        2.07       97.44
                                  7 |        110        1.10       98.54
                                  8 |         43        0.43       98.97
                                  9 |         44        0.44       99.41
                                 10 |         19        0.19       99.60
                                 11 |          7        0.07       99.67
                                 12 |          8        0.08       99.75
                                 13 |          5        0.05       99.80
                                 14 |          5        0.05       99.85
All boxes blank, including None box |         15        0.15      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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