*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970200103
1970000000
1971000000
1972000000
1973200002
1974000000
1975200002
1976100001
1977100001
1978100001
1979300003
1980000000
1981000101
1982000101
1983100001
1984100102
1985300003
1986100102
1987300205
1988000101
1989000404
1990300508
1991100708
1992000404
1993400509
199430011014
199532014019
199620010012
1997100203
1998200709
1999500308
20004006010
200110017018
200211012014
2003000909
200400010010
2005300407
20064007011
2007200507
2008000404
2009010809
2010100405
201110018019
20123009012
201300010010
2014000404
2015000303
2016000000
2017000000
2018000000
Total65402100279