*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992000000
1993000000
1994000000
1995000000
1996000000
1997000000
1998000000
1999010001
2000000000
2001000000
2002000000
2003000000
2004001001
2005040004
2006010001
2007013004
200831710021
2009202004
2010102003
2011001001
2012000000
2013000000
2014010001
2015001001
2016000000
2017000000
Total625110042