Frequencies for first 10,000 rows of totdiag variable in nhamcsopd2000 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      2,163       21.63       21.63
                                  1 |      3,318       33.18       54.81
                                  2 |      2,096       20.96       75.77
                                  3 |      1,151       11.51       87.28
                                  4 |        548        5.48       92.76
                                  5 |        241        2.41       95.17
                                  6 |        129        1.29       96.46
                                  7 |         49        0.49       96.95
                                  8 |         24        0.24       97.19
                                  9 |         16        0.16       97.35
                                 10 |          3        0.03       97.38
                                 11 |          2        0.02       97.40
                                 12 |          1        0.01       97.41
All boxes blank, including None box |        259        2.59      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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