Frequencies for impact2 variable in person dataset :

  PRINCIPAL |
     IMPACT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         24        2.23        2.23
          1 |         47        4.36        6.59
          2 |          4        0.37        6.96
          3 |         82        7.61       14.58
          5 |          5        0.46       15.04
          6 |         32        2.97       18.01
          7 |         21        1.95       19.96
          8 |          2        0.19       20.15
          9 |         74        6.87       27.02
         10 |         55        5.11       32.13
         11 |         34        3.16       35.28
         12 |        455       42.25       77.53
         13 |         49        4.55       82.08
          . |        193       17.92      100.00
------------+-----------------------------------
      Total |      1,077      100.00

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