Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1935 | 1 0.01 0.01 1947 | 1 0.01 0.02 1951 | 1 0.01 0.03 1956 | 1 0.01 0.04 1960 | 1 0.01 0.05 1962 | 1 0.01 0.06 1963 | 4 0.04 0.10 1964 | 5 0.05 0.15 1965 | 9 0.09 0.24 1966 | 7 0.07 0.31 1967 | 10 0.10 0.41 1968 | 6 0.06 0.47 1969 | 7 0.07 0.54 1970 | 12 0.12 0.66 1971 | 6 0.06 0.72 1972 | 15 0.15 0.87 1973 | 12 0.12 0.99 1974 | 9 0.09 1.08 1975 | 4 0.04 1.12 1976 | 11 0.11 1.23 1977 | 22 0.22 1.45 1978 | 23 0.23 1.68 1979 | 33 0.33 2.01 1980 | 23 0.23 2.24 1981 | 28 0.28 2.52 1982 | 36 0.36 2.88 1983 | 35 0.35 3.23 1984 | 72 0.72 3.95 1985 | 85 0.85 4.80 1986 | 111 1.11 5.91 1987 | 146 1.46 7.37 1988 | 172 1.72 9.09 1989 | 252 2.52 11.61 1990 | 264 2.64 14.25 1991 | 305 3.05 17.30 1992 | 326 3.26 20.56 1993 | 415 4.15 24.71 1994 | 413 4.13 28.84 1995 | 512 5.12 33.96 1996 | 493 4.93 38.89 1997 | 525 5.25 44.14 1998 | 519 5.19 49.33 1999 | 577 5.77 55.10 2000 | 681 6.81 61.91 2001 | 705 7.05 68.96 2002 | 633 6.33 75.29 2003 | 680 6.80 82.09 2004 | 685 6.85 88.94 2005 | 730 7.30 96.24 2006 | 51 0.51 96.75 9999 | 325 3.25 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016