Frequencies for type variable in fpreva1998 dataset :

    type of |
     format |      Freq.     Percent        Cum.
------------+-----------------------------------
          C |          2        0.28        0.28
          N |        702       99.72      100.00
------------+-----------------------------------
      Total |        704      100.00

by Jean Roth , jroth@nber.org , 10 May 2016