*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000011
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976001012
1977012003
1978001001
1979002002
1980003003
1981005005
1982003003
1983002002
1984001001
1985004004
1986012003
1987233008
1988021003
1989044008
19901820011
1991232007
1992063009
19931830012
199421560023
19951970017
199631450022
199713980048
199824620050
1999118140033
2000129110041
200122050027
2002025230048
2003014150029
20041801900100
2005137170055
2006035280164
2007331270061
2008124320057
2009028470075
2010031390070
201127510060
2012134290064
2013019250044
2014023240047
201508150023
2016005005
2017000000
Total28622498031151