*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000101
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000101
1985000101
1986000000
1987000000
1988000000
1989000000
1990000101
1991000000
1992000000
1993000000
1994000101
1995000000
1996000000
1997000000
1998000000
1999100001
2000000000
2001000000
2002000000
2003000101
2004000000
2005000000
2006000101
2007000202
2008000101
2009000202
2010000101
2011000000
2012000101
2013000202
2014000314
2015000303
2016000000
2017000000
2018000000
Total10022124