*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980000000
1981000000
1982000000
1983000000
1984000000
1985001001
1986002002
1987003014
1988003003
1989003003
1990002002
199100110011
1992007007
1993009009
199400110011
199500130114
199600100010
199700120012
199800100010
1999006006
2000006006
2001007007
2002005005
20030090211
2004001001
2005006017
2006005005
2007003003
2008002002
200900170017
2010007007
2011005016
2012005038
2013008008
2014000000
2015001001
2016000000
2017000000
Total0019009199