Frequencies for s5_c3_6 variable in hcris2552_10_2015 dataset :

  number of |
   stations |
    s500000 |
00600 00300 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.11        0.11
          2 |          3        0.05        0.16
          4 |          2        0.03        0.19
          6 |          2        0.03        0.22
          9 |          1        0.02        0.24
         12 |          1        0.02        0.26
         26 |          1        0.02        0.27
          . |      6,241       99.73      100.00
------------+-----------------------------------
      Total |      6,258      100.00

by Jean Roth , jroth@nber.org , 23 Aug 2018