*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970002002
1970001001
1971000000
1972000000
1973000000
1974000000
1975002002
1976010001
1977102003
1978000000
1979260008
1980053008
1981013004
1982002002
1983001001
1984011002
1985000000
1986010001
1987031004
1988063009
1989041005
199011820021
1991040004
199201820020
199302820030
19940142500147
199518170089
19963104400111
19971170700178
19988150400162
1999196300100
20002189700198
20013153700163
20021282800291
200343131100328
200413691300383
20051136700144
200602582400282
200724183000450
200861812400211
200932853200320
201083885000446
201122574600305
2012374705600563
2013331714400464
201403633600399
2015008008
201601900019
2017000000
Total915237561005889