*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 197050113524
1970000000
1971200002
1972100001
1973100001
1974000000
1975000000
1976000000
1977200002
1978100001
1979000000
1980000000
1981000011
1982000101
1983003249
1984000000
1985200002
1986100001
1987000000
1988000011
1989000000
1990200002
1991000101
1992100001
1993000101
1994400105
1995100102
1996000000
1997100102
1998100203
1999100001
2000000000
2001000112
2002000101
2003000022
2004100102
2005000213
2006000303
2007010203
2008000415
2009000303
2010000224
2011000202
2012000101
2013100203
2014000000
20150007512
2016000101
2017000101
2018000000
Total281144623112