Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 0 | 1 0.01 0.01 1927 | 1 0.01 0.02 1929 | 1 0.01 0.03 1932 | 2 0.02 0.05 1939 | 1 0.01 0.06 1941 | 1 0.01 0.07 1948 | 3 0.03 0.10 1949 | 2 0.02 0.12 1954 | 1 0.01 0.13 1957 | 1 0.01 0.14 1958 | 3 0.03 0.17 1960 | 1 0.01 0.18 1961 | 2 0.02 0.20 1962 | 3 0.03 0.23 1963 | 5 0.05 0.28 1964 | 6 0.06 0.34 1965 | 9 0.09 0.43 1966 | 18 0.18 0.61 1967 | 13 0.13 0.74 1968 | 18 0.18 0.92 1969 | 18 0.18 1.10 1970 | 25 0.25 1.35 1971 | 30 0.30 1.65 1972 | 40 0.40 2.05 1973 | 22 0.22 2.27 1974 | 34 0.34 2.61 1975 | 30 0.30 2.91 1976 | 46 0.46 3.37 1977 | 53 0.53 3.90 1978 | 78 0.78 4.68 1979 | 101 1.01 5.69 1980 | 61 0.61 6.30 1981 | 96 0.96 7.26 1982 | 127 1.27 8.53 1983 | 145 1.45 9.98 1984 | 220 2.20 12.18 1985 | 278 2.78 14.96 1986 | 354 3.54 18.50 1987 | 402 4.02 22.52 1988 | 400 4.00 26.52 1989 | 484 4.84 31.36 1990 | 455 4.55 35.91 1991 | 507 5.07 40.98 1992 | 478 4.78 45.76 1993 | 532 5.32 51.08 1994 | 620 6.20 57.28 1995 | 696 6.96 64.24 1996 | 542 5.42 69.66 1997 | 656 6.56 76.22 1998 | 619 6.19 82.41 1999 | 741 7.41 89.82 2000 | 706 7.06 96.88 2001 | 80 0.80 97.68 9999 | 232 2.32 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016