*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970003003
1970000000
1971001001
1972001001
1973001001
1974000000
1975001001
1976001001
1977003003
1978001001
1979001001
1980001001
1981000000
1982000000
1983000000
1984000000
1985000000
1986002002
1987002002
1988000000
1989002002
1990001001
1991004004
1992001001
1993001001
1994002002
1995000000
1996002002
1997002002
1998005005
1999002002
2000004004
2001000000
2002003003
2003001001
2004001001
2005001001
2006000000
2007000000
2008002002
2009000000
2010001001
2011001001
2012000000
2013000000
2014000000
2015000000
2016000000
2017000000
Total00540054