Frequencies for impact2 variable in person dataset :

  PRINCIPAL |
     IMPACT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         18        2.21        2.21
          1 |         35        4.29        6.50
          2 |         18        2.21        8.70
          3 |         56        6.86       15.56
          5 |          8        0.98       16.54
          6 |         40        4.90       21.45
          7 |          5        0.61       22.06
          9 |         52        6.37       28.43
         10 |         32        3.92       32.35
         11 |         26        3.19       35.54
         12 |        346       42.40       77.94
         13 |         40        4.90       82.84
          . |        140       17.16      100.00
------------+-----------------------------------
      Total |        816      100.00

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