*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970170019
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000022
1981000011
1982001001
1983000011
1984000000
1985000000
1986000000
1987000000
1988013015
1989001023
1990000000
1991004004
1992015006
1993004015
199402170120
19951650012
1996106007
199700100010
1998044019
199900130114
200015130019
200100130417
2002022202448
2003012003
2004020002
2005041005
2006001001
2007011002
2008002002
2009010001
201000110011
201100100010
2012030003
2013002002
2014111003
2015001001
2016001001
2017000000
Total541154040240