*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970052007
1970000000
1971000000
1972010001
1973030003
1974031004
1975020002
1976000000
1977000000
1978010001
1979000000
1980010001
1981001001
1982011002
1983001001
1984010001
1985000000
1986000000
1987000000
1988001001
1989000000
1990000000
1991000000
1992000000
1993000000
1994001001
1995000000
1996001001
1997001001
1998000000
1999000000
2000000000
2001010001
2002030003
2003000000
2004000000
2005000000
2006000000
2007000000
2008000000
2009000000
2010000000
2011010001
2012011002
2013030003
2014010001
2015000000
2016000000
2017000000
Total028110039