Frequencies for first 10,000 rows of mod_year variable in person dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1924 | 1 0.01 0.01 1954 | 1 0.01 0.02 1963 | 4 0.04 0.06 1964 | 1 0.01 0.07 1965 | 4 0.04 0.11 1966 | 4 0.04 0.15 1967 | 3 0.03 0.18 1968 | 1 0.01 0.19 1969 | 7 0.07 0.26 1970 | 9 0.09 0.35 1971 | 11 0.11 0.46 1972 | 22 0.22 0.68 1973 | 23 0.23 0.91 1974 | 9 0.09 1.00 1975 | 8 0.08 1.08 1976 | 13 0.13 1.21 1977 | 29 0.29 1.50 1978 | 38 0.38 1.88 1979 | 40 0.40 2.28 1980 | 26 0.26 2.54 1981 | 27 0.27 2.81 1982 | 50 0.50 3.31 1983 | 74 0.74 4.05 1984 | 96 0.96 5.01 1985 | 151 1.51 6.52 1986 | 152 1.52 8.04 1987 | 179 1.79 9.83 1988 | 232 2.32 12.15 1989 | 281 2.81 14.96 1990 | 317 3.17 18.13 1991 | 348 3.48 21.61 1992 | 365 3.65 25.26 1993 | 432 4.32 29.58 1994 | 472 4.72 34.30 1995 | 616 6.16 40.46 1996 | 647 6.47 46.93 1997 | 605 6.05 52.98 1998 | 652 6.52 59.50 1999 | 604 6.04 65.54 2000 | 672 6.72 72.26 2001 | 566 5.66 77.92 2002 | 767 7.67 85.59 2003 | 558 5.58 91.17 2004 | 32 0.32 91.49 9999 | 220 2.20 93.69 . | 631 6.31 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016