Frequencies for p9 variable in miper dataset :

         p9 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        556       67.97       67.97
          1 |          1        0.12       68.09
          2 |          6        0.73       68.83
          3 |          6        0.73       69.56
          4 |          9        1.10       70.66
          5 |          5        0.61       71.27
          6 |          6        0.73       72.00
          7 |          6        0.73       72.74
          8 |          6        0.73       73.47
          9 |         10        1.22       74.69
         10 |         13        1.59       76.28
         11 |          7        0.86       77.14
         12 |         11        1.34       78.48
         13 |          8        0.98       79.46
         14 |          8        0.98       80.44
         15 |         17        2.08       82.52
         16 |         10        1.22       83.74
         17 |         13        1.59       85.33
         18 |          8        0.98       86.31
         19 |         15        1.83       88.14
         20 |         11        1.34       89.49
         21 |          5        0.61       90.10
         22 |         12        1.47       91.56
         23 |          9        1.10       92.67
         24 |          6        0.73       93.40
         25 |          7        0.86       94.25
         26 |          5        0.61       94.87
         27 |          7        0.86       95.72
         28 |         10        1.22       96.94
         29 |          7        0.86       97.80
         30 |          4        0.49       98.29
         31 |          4        0.49       98.78
         32 |          3        0.37       99.14
         34 |          1        0.12       99.27
         36 |          2        0.24       99.51
         37 |          1        0.12       99.63
         39 |          1        0.12       99.76
         41 |          1        0.12       99.88
         44 |          1        0.12      100.00
------------+-----------------------------------
      Total |        818      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016