*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000101
1977000101
1978000000
1979000000
1980000000
1981000000
1982000101
1983000000
1984000000
1985000000
1986000000
1987000303
1988000000
1989000000
1990000000
1991000202
1992000303
1993000101
1994000202
1995000101
1996000505
1997000202
1998000101
1999000404
2000000303
2001000404
2002000101
2003000404
2004000101
2005000404
2006000303
2007000707
2008000404
2009000505
201000018018
2011000404
2012000000
2013000101
2014000000
2015000000
2016000101
2017000000
2018000000
Total00087087