*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970000000
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000011
1980000000
1981000000
1982000000
1983000000
1984000000
1985000000
1986000101
1987000101
1988000000
1989000303
1990000213
1991001405
1992002204
1993001102
1994000437
19950016310
1996000213
1997001102
1998000617
1999000415
2000000213
2001000404
200200011011
2003000729
200400039342
20050003710
200600422329
200700023427
2008000617
2009000404
201000134136
2011000707
2012000101
2013000112
2014000213
2015000101
2016000101
2017000000
2018000000
Total001120535251