*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970001001
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988000000
1989000000
1990000000
1991000000
1992000000
1993001001
1994000000
1995001001
1996003003
1997003003
1998001001
1999001001
2000001001
2001001001
2002004004
2003003003
2004000000
2005002002
2006003003
2007006006
2008004004
2009004004
2010007007
2011004004
2012002002
2013000000
2014000000
2015000000
2016001001
2017000000
Total00530053