Frequencies for planid variable in mmp2018 dataset :

    Plan ID |      Freq.     Percent        Cum.
------------+-----------------------------------
            |          1        0.28        0.28
        001 |        353       98.06       98.33
        002 |          4        1.11       99.44
        005 |          1        0.28       99.72
        006 |          1        0.28      100.00
------------+-----------------------------------
      Total |        360      100.00

by Jean Roth , jroth@nber.org , 10 Sep 2018