*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000101
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991100001
1992200204
1993000101
1994100001
1995010405
1996000303
1997000101
1998000101
1999200204
2000100102
2001000202
2002100203
2003000303
2004000101
2005000303
2006100203
2007200103
2008000000
2009000202
2010000202
2011000202
2012000000
2013100001
2014000000
2015000000
2016000000
2017000000
2018000000
Total121036049