Frequencies for first 10,000 rows of a_mod_yr variable in veh_aux dataset : Vehicle | Model Year | Freq. Percent Cum. ------------+----------------------------------- 1931 | 1 0.01 0.01 1949 | 1 0.01 0.02 1953 | 1 0.01 0.03 1954 | 1 0.01 0.04 1955 | 2 0.02 0.06 1956 | 3 0.03 0.09 1957 | 2 0.02 0.11 1958 | 6 0.06 0.17 1959 | 10 0.10 0.27 1960 | 4 0.04 0.31 1961 | 6 0.06 0.37 1962 | 9 0.09 0.46 1963 | 9 0.09 0.55 1964 | 14 0.14 0.69 1965 | 33 0.33 1.02 1966 | 42 0.42 1.44 1967 | 40 0.40 1.84 1968 | 53 0.53 2.37 1969 | 61 0.61 2.98 1970 | 72 0.72 3.70 1971 | 77 0.77 4.47 1972 | 124 1.24 5.71 1973 | 142 1.42 7.13 1974 | 149 1.49 8.62 1975 | 120 1.20 9.82 1976 | 188 1.88 11.70 1977 | 283 2.83 14.53 1978 | 374 3.74 18.27 1979 | 468 4.68 22.95 1980 | 337 3.37 26.32 1981 | 387 3.87 30.19 1982 | 389 3.89 34.08 1983 | 421 4.21 38.29 1984 | 605 6.05 44.34 1985 | 663 6.63 50.97 1986 | 733 7.33 58.30 1987 | 648 6.48 64.78 1988 | 695 6.95 71.73 1989 | 693 6.93 78.66 1990 | 641 6.41 85.07 1991 | 689 6.89 91.96 1992 | 516 5.16 97.12 1993 | 43 0.43 97.55 9999 | 245 2.45 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016