*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977001001
1978000000
1979001001
1980000000
1981002002
1982000000
1983000000
1984000000
1985001001
1986002002
1987004004
1988004004
1989002002
1990005005
199100140014
199200110011
1993009009
1994009009
199500170017
199600110011
199700120012
199800130013
1999008008
200000150015
200100150015
200200270027
200300130013
2004009009
2005009009
200600100010
200700160016
2008006006
200900160016
201000150015
201100180018
2012005005
2013001001
2014004004
2015004004
2016000000
2017000000
Total0030900309