Frequencies for s5_c4_6 variable in hcris2552_10_2016 dataset :

  number of |
   stations |
    s500000 |
00600 00400 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         13        0.21        0.21
          2 |          5        0.08        0.29
          3 |          3        0.05        0.34
          4 |          4        0.06        0.40
          6 |          1        0.02        0.42
          7 |          1        0.02        0.44
          . |      6,155       99.56      100.00
------------+-----------------------------------
      Total |      6,182      100.00

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