Frequencies for a_mod_yr variable in veh_aux dataset : Vehicle | Model Year | Freq. Percent Cum. ------------+----------------------------------- 1964 | 3 0.39 0.39 1966 | 1 0.13 0.52 1967 | 2 0.26 0.77 1968 | 2 0.26 1.03 1969 | 2 0.26 1.29 1970 | 3 0.39 1.68 1971 | 1 0.13 1.80 1972 | 10 1.29 3.09 1973 | 8 1.03 4.12 1974 | 6 0.77 4.90 1975 | 5 0.64 5.54 1976 | 8 1.03 6.57 1977 | 12 1.55 8.12 1978 | 14 1.80 9.92 1979 | 19 2.45 12.37 1980 | 17 2.19 14.56 1981 | 28 3.61 18.17 1982 | 12 1.55 19.72 1983 | 27 3.48 23.20 1984 | 35 4.51 27.71 1985 | 35 4.51 32.22 1986 | 45 5.80 38.02 1987 | 40 5.15 43.17 1988 | 33 4.25 47.42 1989 | 50 6.44 53.87 1990 | 51 6.57 60.44 1991 | 31 3.99 64.43 1992 | 30 3.87 68.30 1993 | 36 4.64 72.94 1994 | 60 7.73 80.67 1995 | 58 7.47 88.14 1996 | 43 5.54 93.69 1997 | 1 0.13 93.81 9999 | 48 6.19 100.00 ------------+----------------------------------- Total | 776 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016