Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : MODEL YEAR | Freq. Percent Cum. ------------+----------------------------------- 1941 | 1 0.01 0.01 1946 | 1 0.01 0.02 1948 | 1 0.01 0.03 1951 | 1 0.01 0.04 1952 | 1 0.01 0.05 1954 | 2 0.02 0.07 1959 | 1 0.01 0.08 1960 | 1 0.01 0.09 1961 | 1 0.01 0.10 1962 | 1 0.01 0.11 1963 | 2 0.02 0.13 1964 | 1 0.01 0.14 1965 | 3 0.03 0.17 1966 | 1 0.01 0.18 1967 | 3 0.03 0.21 1968 | 3 0.03 0.24 1969 | 7 0.07 0.31 1970 | 7 0.07 0.38 1971 | 7 0.07 0.45 1972 | 6 0.06 0.51 1973 | 6 0.06 0.57 1974 | 4 0.04 0.61 1975 | 2 0.02 0.63 1976 | 9 0.09 0.72 1977 | 15 0.15 0.87 1978 | 6 0.06 0.93 1979 | 9 0.09 1.02 1980 | 14 0.14 1.16 1981 | 11 0.11 1.27 1982 | 22 0.22 1.49 1983 | 22 0.22 1.71 1984 | 39 0.39 2.10 1985 | 50 0.50 2.60 1986 | 61 0.61 3.21 1987 | 87 0.87 4.08 1988 | 91 0.91 4.99 1989 | 123 1.23 6.22 1990 | 173 1.73 7.95 1991 | 196 1.96 9.91 1992 | 188 1.88 11.79 1993 | 285 2.85 14.64 1994 | 311 3.11 17.75 1995 | 333 3.33 21.08 1996 | 361 3.61 24.69 1997 | 446 4.46 29.15 1998 | 499 4.99 34.14 1999 | 571 5.71 39.85 2000 | 641 6.41 46.26 2001 | 560 5.60 51.86 2002 | 590 5.90 57.76 2003 | 672 6.72 64.48 2004 | 677 6.77 71.25 2005 | 700 7.00 78.25 2006 | 725 7.25 85.50 2007 | 780 7.80 93.30 2008 | 391 3.91 97.21 2009 | 32 0.32 97.53 9999 | 247 2.47 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016