Frequencies for pmodyear variable in parkwork dataset : vehicle | model year | Freq. Percent Cum. ------------+----------------------------------- 1961 | 1 0.09 0.09 1968 | 1 0.09 0.17 1970 | 3 0.26 0.44 1971 | 1 0.09 0.52 1972 | 2 0.17 0.70 1978 | 1 0.09 0.79 1979 | 3 0.26 1.05 1980 | 2 0.17 1.22 1982 | 1 0.09 1.31 1984 | 3 0.26 1.57 1986 | 6 0.52 2.09 1987 | 4 0.35 2.44 1988 | 6 0.52 2.97 1989 | 6 0.52 3.49 1990 | 7 0.61 4.10 1991 | 4 0.35 4.45 1992 | 11 0.96 5.41 1993 | 17 1.48 6.89 1994 | 14 1.22 8.12 1995 | 31 2.71 10.82 1996 | 36 3.14 13.96 1997 | 40 3.49 17.45 1998 | 36 3.14 20.59 1999 | 66 5.76 26.35 2000 | 68 5.93 32.29 2001 | 51 4.45 36.74 2002 | 51 4.45 41.19 2003 | 75 6.54 47.73 2004 | 54 4.71 52.44 2005 | 75 6.54 58.99 2006 | 67 5.85 64.83 2007 | 59 5.15 69.98 2008 | 61 5.32 75.31 2009 | 40 3.49 78.80 2010 | 42 3.66 82.46 2011 | 57 4.97 87.43 2012 | 70 6.11 93.54 2013 | 32 2.79 96.34 2014 | 9 0.79 97.12 9999 | 33 2.88 100.00 ------------+----------------------------------- Total | 1,146 100.00 by Jean Roth , jroth@nber.org , 22 Oct 2016