Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1924 | 1 0.01 0.01 1948 | 1 0.01 0.02 1952 | 1 0.01 0.03 1954 | 1 0.01 0.04 1962 | 3 0.03 0.07 1963 | 3 0.03 0.10 1964 | 3 0.03 0.13 1965 | 7 0.07 0.20 1966 | 9 0.09 0.29 1967 | 8 0.08 0.37 1968 | 3 0.03 0.40 1969 | 10 0.10 0.50 1970 | 19 0.19 0.69 1971 | 9 0.09 0.78 1972 | 22 0.22 1.00 1973 | 30 0.30 1.30 1974 | 13 0.13 1.43 1975 | 8 0.08 1.51 1976 | 16 0.16 1.67 1977 | 36 0.36 2.03 1978 | 41 0.41 2.44 1979 | 43 0.43 2.87 1980 | 32 0.32 3.19 1981 | 41 0.41 3.60 1982 | 52 0.52 4.12 1983 | 89 0.89 5.01 1984 | 109 1.09 6.10 1985 | 154 1.54 7.64 1986 | 189 1.89 9.53 1987 | 218 2.18 11.71 1988 | 262 2.62 14.33 1989 | 352 3.52 17.85 1990 | 349 3.49 21.34 1991 | 377 3.77 25.11 1992 | 398 3.98 29.09 1993 | 440 4.40 33.49 1994 | 470 4.70 38.19 1995 | 626 6.26 44.45 1996 | 548 5.48 49.93 1997 | 576 5.76 55.69 1998 | 639 6.39 62.08 1999 | 656 6.56 68.64 2000 | 733 7.33 75.97 2001 | 690 6.90 82.87 2002 | 748 7.48 90.35 2003 | 624 6.24 96.59 2004 | 50 0.50 97.09 9999 | 291 2.91 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016