*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970005005
1970000000
1971000000
1972000000
1973002002
1974002002
1975000000
1976000000
1977000000
1978000000
1979000000
1980002002
1981001001
1982000000
1983002002
1984000000
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992001001
1993002002
1994003003
1995004004
1996000000
1997000000
1998000000
1999000000
2000000000
2001001001
2002000000
2003000000
2004001001
2005000000
2006000000
2007000000
2008005005
2009003003
2010000000
2011003003
2012001001
2013000000
2014001001
2015001001
2016000000
2017000000
Total00400040