*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197010130014
1970000000
1971000000
1972000000
1973000000
1974050005
1975101002
1976014005
1977114130028
197871240032
1979738330078
198048220034
1981116160033
198232150020
198356292900114
1984126235200201
198556120023
198602110013
19871812140044
198852402600118
1989117009
19901180010
1991114660081
1992133190053
199332286500125
19944516100116
199546130023
199614326100107
19977836100151
19981412723900380
19994613710300286
200075796200216
2001526200051
20021546350096
20033816370091
200416320039
200525160023
20061322170052
2007812120032
20082725220074
20091922310072
20102739280094
201133752100129
201214740052
2013102003
2014012003
Total68211211329003132