*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970003003
1970000000
1971000000
1972000000
1973000000
1974000000
1975001001
1976000000
1977001001
1978001001
1979004004
1980002002
1981001001
1982002002
1983000000
1984000000
1985000000
1986008008
1987006006
1988004004
1989007007
1990009009
199100250025
199200180018
199300210021
199400210021
199500240024
199600190019
199700190019
199800140014
199900170017
200000170017
200100180018
200200240024
200300300030
200400190019
200500160016
200600190019
200700200020
200800220022
200900400040
201000280028
201100260026
201200220022
2013006006
2014003003
2015003003
2016000000
2017001001
Total0054100541