Frequencies for p4 variable in miper dataset :

         p4 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        570       69.01       69.01
          1 |          2        0.24       69.25
          2 |         11        1.33       70.58
          3 |          7        0.85       71.43
          4 |          8        0.97       72.40
          5 |         14        1.69       74.09
          6 |         15        1.82       75.91
          7 |          4        0.48       76.39
          8 |          9        1.09       77.48
          9 |         11        1.33       78.81
         10 |          9        1.09       79.90
         11 |          9        1.09       80.99
         12 |          9        1.09       82.08
         13 |          7        0.85       82.93
         14 |         11        1.33       84.26
         15 |         10        1.21       85.47
         16 |         13        1.57       87.05
         17 |         10        1.21       88.26
         18 |          9        1.09       89.35
         19 |          9        1.09       90.44
         20 |          5        0.61       91.04
         21 |          6        0.73       91.77
         22 |          3        0.36       92.13
         23 |          9        1.09       93.22
         24 |         11        1.33       94.55
         25 |          8        0.97       95.52
         26 |          4        0.48       96.00
         27 |          6        0.73       96.73
         28 |          4        0.48       97.22
         29 |          2        0.24       97.46
         30 |          2        0.24       97.70
         31 |          2        0.24       97.94
         32 |          7        0.85       98.79
         34 |          1        0.12       98.91
         35 |          4        0.48       99.39
         37 |          1        0.12       99.52
         39 |          1        0.12       99.64
         40 |          2        0.24       99.88
         41 |          1        0.12      100.00
------------+-----------------------------------
      Total |        826      100.00

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