*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197000170219
1970003014
1971003003
1972000000
1973000000
1974002002
1975000000
1976000011
1977002002
1978001001
1979000000
1980000000
1981002002
1982000000
1983000000
1984002002
1985002002
1986001001
1987001001
1988001001
1989000000
1990000000
1991003003
1992000000
1993000000
1994001001
1995002002
1996000000
1997000000
1998000000
1999001001
2000001001
2001000000
2002000000
2003000000
2004000000
2005000000
2006000000
2007002002
2008000000
2009001001
2010000000
2011000000
2012000000
2013000000
2014000000
2015000000
2016000000
2017000000
Total00480452