Frequencies for first 10,000 rows of mod_year variable in person dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1946 | 1 0.01 0.01 1952 | 1 0.01 0.02 1954 | 1 0.01 0.03 1959 | 1 0.01 0.04 1963 | 2 0.02 0.06 1965 | 1 0.01 0.07 1966 | 1 0.01 0.08 1967 | 1 0.01 0.09 1968 | 4 0.04 0.13 1969 | 6 0.06 0.19 1970 | 4 0.04 0.23 1971 | 6 0.06 0.29 1972 | 7 0.07 0.36 1973 | 1 0.01 0.37 1974 | 4 0.04 0.41 1975 | 1 0.01 0.42 1976 | 6 0.06 0.48 1977 | 12 0.12 0.60 1978 | 6 0.06 0.66 1979 | 6 0.06 0.72 1980 | 14 0.14 0.86 1981 | 10 0.10 0.96 1982 | 14 0.14 1.10 1983 | 18 0.18 1.28 1984 | 33 0.33 1.61 1985 | 43 0.43 2.04 1986 | 67 0.67 2.71 1987 | 80 0.80 3.51 1988 | 91 0.91 4.42 1989 | 141 1.41 5.83 1990 | 141 1.41 7.24 1991 | 169 1.69 8.93 1992 | 174 1.74 10.67 1993 | 256 2.56 13.23 1994 | 264 2.64 15.87 1995 | 298 2.98 18.85 1996 | 359 3.59 22.44 1997 | 425 4.25 26.69 1998 | 510 5.10 31.79 1999 | 588 5.88 37.67 2000 | 680 6.80 44.47 2001 | 609 6.09 50.56 2002 | 597 5.97 56.53 2003 | 649 6.49 63.02 2004 | 640 6.40 69.42 2005 | 654 6.54 75.96 2006 | 598 5.98 81.94 2007 | 648 6.48 88.42 2008 | 307 3.07 91.49 2009 | 17 0.17 91.66 9999 | 169 1.69 93.35 . | 665 6.65 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016