*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
1991000112
1992000000
1993000000
1994000426
1995000303
1996000213
1997000000
1998000101
1999000202
2000000202
2001000101
2002000202
2003000303
2004000011
2005000000
2006000011
2007000000
2008000303
2009000000
2010000404
2011000101
2012000011
2013000101
2014000000
2015000000
2016000000
2017000000
2018000000
Total00030737