*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970400004
1970000000
1971100001
1972000000
1973100001
1974000000
1975000000
1976000000
1977000000
1978000101
1979100203
1980000101
1981300104
1982200103
1983200002
1984000101
1985100203
1986100405
1987400408
1988100607
1989100506
19901009010
199100025025
199200024024
199300024024
199420034036
199510041042
199600028028
199740036040
199810022023
199940019023
200000017017
200120029031
200210021022
200310015016
200400018018
200500011011
200600015015
200760011017
200810014015
200900036036
201000033033
201100027027
201230012015
201300027027
2014000101
2015000202
2016000202
2017000000
2018000000
Total49005810630