Frequencies for pmodyear variable in parkwork dataset : vehicle | model year | Freq. Percent Cum. ------------+----------------------------------- 1960 | 1 0.09 0.09 1963 | 1 0.09 0.18 1966 | 1 0.09 0.27 1970 | 1 0.09 0.37 1971 | 1 0.09 0.46 1974 | 1 0.09 0.55 1976 | 1 0.09 0.64 1978 | 1 0.09 0.73 1981 | 1 0.09 0.82 1982 | 1 0.09 0.92 1983 | 1 0.09 1.01 1984 | 3 0.27 1.28 1985 | 3 0.27 1.56 1986 | 5 0.46 2.02 1987 | 3 0.27 2.29 1988 | 7 0.64 2.93 1989 | 11 1.01 3.94 1990 | 10 0.92 4.86 1991 | 10 0.92 5.77 1992 | 12 1.10 6.87 1993 | 6 0.55 7.42 1994 | 18 1.65 9.07 1995 | 29 2.66 11.73 1996 | 30 2.75 14.48 1997 | 55 5.04 19.52 1998 | 55 5.04 24.56 1999 | 54 4.95 29.51 2000 | 75 6.87 36.39 2001 | 53 4.86 41.25 2002 | 62 5.68 46.93 2003 | 59 5.41 52.34 2004 | 66 6.05 58.39 2005 | 66 6.05 64.44 2006 | 76 6.97 71.40 2007 | 58 5.32 76.72 2008 | 58 5.32 82.03 2009 | 33 3.02 85.06 2010 | 40 3.67 88.73 2011 | 52 4.77 93.49 2012 | 42 3.85 97.34 2013 | 5 0.46 97.80 9998 | 1 0.09 97.89 9999 | 23 2.11 100.00 ------------+----------------------------------- Total | 1,091 100.00 by Jean Roth , jroth@nber.org , 22 Oct 2016