*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970002002
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984001001
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992000000
1993000000
1994001001
1995000000
1996001001
1997000000
1998001001
1999001001
2000000000
2001000000
2002003003
2003000000
2004002002
2005002002
2006001001
2007001001
2008001001
2009001001
2010003003
2011007007
2012002002
2013000000
2014000000
2015000000
2016000000
2017000000
Total00300030