Frequencies for first 10,000 rows of prov4180 variable in posclia2008 dataset :

  number of |
  lab sites |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,576       95.76       95.76
          2 |        183        1.83       97.59
          3 |         83        0.83       98.42
          4 |         34        0.34       98.76
          5 |         20        0.20       98.96
          6 |         18        0.18       99.14
          7 |         12        0.12       99.26
          8 |          6        0.06       99.32
          9 |          9        0.09       99.41
         10 |          9        0.09       99.50
         11 |          4        0.04       99.54
         12 |          5        0.05       99.59
         13 |          2        0.02       99.61
         14 |          1        0.01       99.62
         15 |          6        0.06       99.68
         16 |          3        0.03       99.71
         17 |          3        0.03       99.74
         18 |          3        0.03       99.77
         19 |          6        0.06       99.83
         20 |          2        0.02       99.85
         22 |          1        0.01       99.86
         23 |          1        0.01       99.87
         24 |          2        0.02       99.89
         27 |          2        0.02       99.91
         31 |          1        0.01       99.92
         32 |          2        0.02       99.94
         43 |          1        0.01       99.95
         65 |          1        0.01       99.96
         70 |          1        0.01       99.97
         90 |          1        0.01       99.98
        138 |          1        0.01       99.99
        315 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016