Frequencies for s5_c3_6 variable in hcris2552_10_2012 dataset :

  number of |
   stations |
    s500000 |
00600 00300 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          7        0.11        0.11
          2 |          5        0.08        0.19
          3 |          1        0.02        0.21
          4 |          2        0.03        0.24
          6 |          1        0.02        0.26
         26 |          1        0.02        0.27
          . |      6,210       99.73      100.00
------------+-----------------------------------
      Total |      6,227      100.00

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