*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 1970101079
1970000000
1971000000
1972000000
1973000000
1974000000
1975000000
1976000000
1977000000
1978000000
1979000000
1980200002
1981100001
1982000101
1983100001
1984000000
1985000000
1986000000
1987000000
1988100315
1989200103
1990000000
1991000404
1992000516
1993100405
199410017220
19950015612
1996001607
199700010010
1998100449
199910013014
200000113519
200140013017
2002240022248
2003000213
2004000022
2005000145
2006000101
2007000112
2008000202
2009000011
201000011011
201100010010
2012000033
2013000202
2014001113
2015000101
2016000101
2017000000
2018000000
Total400515441240