*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977001001
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992000000
1993000000
1994000000
1995002002
1996110002
1997010001
1998000000
1999110002
2000200002
2001300003
2002043007
2003131005
2004131005
2005001001
2006020002
2007003003
2008002002
2009001001
2010000000
2011012003
2012000000
2013030003
2014032005
2015011002
2016000000
2017000000
Total923200052