*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970004004
1970002002
1971001001
1972000000
1973002002
1974000000
1975000000
1976001001
1977000000
1978000000
1979000000
1980000000
1981001001
1982000000
1983000000
1984000000
1985000000
1986000000
1987000000
1988001001
1989000000
1990000000
1991000000
1992000000
1993000000
1994000000
1995000000
1996001001
1997001001
1998001001
1999001001
2000003003
2001000000
2002001001
2003000000
2004000000
2005000000
2006000000
2007002002
2008000000
2009001001
2010000000
2011000000
2012002002
2013000000
2014000000
2015000000
2016001001
2017000000
Total00260026