Frequencies for s5_c3_6 variable in hcris2552_10_2016 dataset :

  number of |
   stations |
    s500000 |
00600 00300 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          6        0.10        0.10
          2 |          4        0.06        0.16
          4 |          2        0.03        0.19
          6 |          2        0.03        0.23
         12 |          1        0.02        0.24
          . |      6,167       99.76      100.00
------------+-----------------------------------
      Total |      6,182      100.00

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