*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972001001
1973000000
1974000000
1975000000
1976000000
1977001001
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985001001
1986000000
1987000000
1988000000
1989000000
1990001001
1991000000
1992002002
1993002002
1994000000
1995000000
1996002002
1997001001
1998002002
1999001001
2000000000
2001001001
2002003003
2003001001
2004001001
2005006006
2006002002
2007005005
2008001001
2009003003
2010002002
2011002002
2012000000
2013000000
2014001001
2015000000
2016000000
2017000000
Total00420042