*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970200002
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000303
1983000000
1984100708
1985000000
1986100001
1987100001
1988100001
1989100102
1990100001
1991000101
1992100001
1993100618
1994200002
1995100001
1996300205
1997000101
199810111114
1999100001
2000200013
2001500005
2002100304
2003300205
20041028112
200560212020
200630123027
200761130038
200820010012
200900015015
2010300122843
2011000251237
201220063240
201310246756
201400026733
2015000202
2016000000
2017000011
2018000000
Total531925291406