Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1927 | 2 0.02 0.02 1940 | 1 0.01 0.03 1944 | 1 0.01 0.04 1949 | 1 0.01 0.05 1951 | 1 0.01 0.06 1953 | 1 0.01 0.07 1954 | 1 0.01 0.08 1958 | 1 0.01 0.09 1959 | 5 0.05 0.14 1960 | 3 0.03 0.17 1961 | 4 0.04 0.21 1962 | 1 0.01 0.22 1963 | 6 0.06 0.28 1964 | 11 0.11 0.39 1965 | 19 0.19 0.58 1966 | 18 0.18 0.76 1967 | 16 0.16 0.92 1968 | 19 0.19 1.11 1969 | 38 0.38 1.49 1970 | 28 0.28 1.77 1971 | 32 0.32 2.09 1972 | 42 0.42 2.51 1973 | 57 0.57 3.08 1974 | 46 0.46 3.54 1975 | 45 0.45 3.99 1976 | 65 0.65 4.64 1977 | 76 0.76 5.40 1978 | 109 1.09 6.49 1979 | 131 1.31 7.80 1980 | 123 1.23 9.03 1981 | 138 1.38 10.41 1982 | 167 1.67 12.08 1983 | 186 1.86 13.94 1984 | 314 3.14 17.08 1985 | 426 4.26 21.34 1986 | 481 4.81 26.15 1987 | 506 5.06 31.21 1988 | 566 5.66 36.87 1989 | 580 5.80 42.67 1990 | 503 5.03 47.70 1991 | 545 5.45 53.15 1992 | 529 5.29 58.44 1993 | 596 5.96 64.40 1994 | 667 6.67 71.07 1995 | 724 7.24 78.31 1996 | 608 6.08 84.39 1997 | 710 7.10 91.49 1998 | 564 5.64 97.13 1999 | 53 0.53 97.66 9999 | 234 2.34 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016