Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1931 | 1 0.01 0.01 1949 | 1 0.01 0.02 1950 | 2 0.02 0.04 1953 | 1 0.01 0.05 1955 | 1 0.01 0.06 1957 | 2 0.02 0.08 1958 | 1 0.01 0.09 1959 | 2 0.02 0.11 1960 | 1 0.01 0.12 1961 | 2 0.02 0.14 1962 | 2 0.02 0.16 1963 | 4 0.04 0.20 1964 | 9 0.09 0.29 1965 | 12 0.12 0.41 1966 | 12 0.12 0.53 1967 | 11 0.11 0.64 1968 | 4 0.04 0.68 1969 | 18 0.18 0.86 1970 | 13 0.13 0.99 1971 | 15 0.15 1.14 1972 | 28 0.28 1.42 1973 | 30 0.30 1.72 1974 | 32 0.32 2.04 1975 | 16 0.16 2.20 1976 | 27 0.27 2.47 1977 | 32 0.32 2.79 1978 | 52 0.52 3.31 1979 | 58 0.58 3.89 1980 | 44 0.44 4.33 1981 | 72 0.72 5.05 1982 | 64 0.64 5.69 1983 | 103 1.03 6.72 1984 | 194 1.94 8.66 1985 | 233 2.33 10.99 1986 | 288 2.88 13.87 1987 | 299 2.99 16.86 1988 | 424 4.24 21.10 1989 | 438 4.38 25.48 1990 | 466 4.66 30.14 1991 | 450 4.50 34.64 1992 | 421 4.21 38.85 1993 | 509 5.09 43.94 1994 | 604 6.04 49.98 1995 | 638 6.38 56.36 1996 | 583 5.83 62.19 1997 | 655 6.55 68.74 1998 | 614 6.14 74.88 1999 | 672 6.72 81.60 2000 | 859 8.59 90.19 2001 | 663 6.63 96.82 2002 | 55 0.55 97.37 9999 | 263 2.63 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016