Frequencies for first 10,000 rows of mod_year variable in vehicle dataset : vehicle | model year | Freq. Percent Cum. ------------+----------------------------------- 1931 | 1 0.01 0.01 1932 | 1 0.01 0.02 1933 | 1 0.01 0.03 1942 | 1 0.01 0.04 1948 | 1 0.01 0.05 1950 | 1 0.01 0.06 1958 | 1 0.01 0.07 1963 | 1 0.01 0.08 1965 | 2 0.02 0.10 1966 | 4 0.04 0.14 1967 | 1 0.01 0.15 1968 | 2 0.02 0.17 1969 | 2 0.02 0.19 1970 | 3 0.03 0.22 1971 | 4 0.04 0.26 1972 | 3 0.03 0.29 1973 | 8 0.08 0.37 1974 | 2 0.02 0.39 1975 | 1 0.01 0.40 1976 | 5 0.05 0.45 1977 | 3 0.03 0.48 1978 | 3 0.03 0.51 1979 | 5 0.05 0.56 1980 | 3 0.03 0.59 1981 | 4 0.04 0.63 1982 | 9 0.09 0.72 1983 | 11 0.11 0.83 1984 | 8 0.08 0.91 1985 | 23 0.23 1.14 1986 | 23 0.23 1.37 1987 | 33 0.33 1.70 1988 | 30 0.30 2.00 1989 | 32 0.32 2.32 1990 | 70 0.70 3.02 1991 | 91 0.91 3.93 1992 | 97 0.97 4.90 1993 | 99 0.99 5.89 1994 | 134 1.34 7.23 1995 | 194 1.94 9.17 1996 | 187 1.87 11.04 1997 | 282 2.82 13.86 1998 | 298 2.98 16.84 1999 | 358 3.58 20.42 2000 | 425 4.25 24.67 2001 | 466 4.66 29.33 2002 | 486 4.86 34.19 2003 | 561 5.61 39.80 2004 | 520 5.20 45.00 2005 | 593 5.93 50.93 2006 | 639 6.39 57.32 2007 | 618 6.18 63.50 2008 | 441 4.41 67.91 2009 | 321 3.21 71.12 2010 | 321 3.21 74.33 2011 | 354 3.54 77.87 2012 | 424 4.24 82.11 2013 | 484 4.84 86.95 2014 | 525 5.25 92.20 2015 | 400 4.00 96.20 2016 | 39 0.39 96.59 9998 | 1 0.01 96.60 9999 | 340 3.40 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Oct 2016