Frequencies for first 10,000 rows of totdiag variable in namcs2000 dataset :

    total # of diagnostic/screening |
                           services |      Freq.     Percent        Cum.
------------------------------------+-----------------------------------
                                  0 |      2,729       27.29       27.29
                                  1 |      3,628       36.28       63.57
                                  2 |      1,626       16.26       79.83
                                  3 |        793        7.93       87.76
                                  4 |        475        4.75       92.51
                                  5 |        223        2.23       94.74
                                  6 |        146        1.46       96.20
                                  7 |         84        0.84       97.04
                                  8 |         60        0.60       97.64
                                  9 |         38        0.38       98.02
                                 10 |         25        0.25       98.27
                                 11 |         19        0.19       98.46
                                 12 |          5        0.05       98.51
                                 13 |          2        0.02       98.53
                                 14 |          1        0.01       98.54
                                 16 |          1        0.01       98.55
All boxes blank, including None box |        145        1.45      100.00
------------------------------------+-----------------------------------
                              Total |     10,000      100.00

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