Frequencies for first 10,000 rows of mod_year variable in person dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1929 | 2 0.02 0.02 1931 | 1 0.01 0.03 1946 | 2 0.02 0.05 1948 | 1 0.01 0.06 1951 | 3 0.03 0.09 1952 | 1 0.01 0.10 1955 | 2 0.02 0.12 1959 | 4 0.04 0.16 1963 | 8 0.08 0.24 1964 | 5 0.05 0.29 1965 | 9 0.09 0.38 1966 | 17 0.17 0.55 1967 | 11 0.11 0.66 1968 | 12 0.12 0.78 1969 | 17 0.17 0.95 1970 | 35 0.35 1.30 1971 | 35 0.35 1.65 1972 | 23 0.23 1.88 1973 | 39 0.39 2.27 1974 | 31 0.31 2.58 1975 | 22 0.22 2.80 1976 | 50 0.50 3.30 1977 | 82 0.82 4.12 1978 | 76 0.76 4.88 1979 | 97 0.97 5.85 1980 | 94 0.94 6.79 1981 | 103 1.03 7.82 1982 | 112 1.12 8.94 1983 | 181 1.81 10.75 1984 | 260 2.60 13.35 1985 | 293 2.93 16.28 1986 | 386 3.86 20.14 1987 | 415 4.15 24.29 1988 | 443 4.43 28.72 1989 | 581 5.81 34.53 1990 | 478 4.78 39.31 1991 | 491 4.91 44.22 1992 | 494 4.94 49.16 1993 | 542 5.42 54.58 1994 | 608 6.08 60.66 1995 | 644 6.44 67.10 1996 | 510 5.10 72.20 1997 | 636 6.36 78.56 1998 | 658 6.58 85.14 1999 | 573 5.73 90.87 2000 | 47 0.47 91.34 9999 | 173 1.73 93.07 . | 693 6.93 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016