*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19754
19762
19770
197819
19793
19803
19811
19828
198327
198413
19859
19869
19873
19888
19894
199021
19917
19922
199317
199445
199563
199681
1997385
1998234
1999636
2000347
2001245
2002219
2003411
2004468
2005379
2006447
20071125
2008559
2009942
2010798
2011517
2012426
2013367
201458
20150
20160
20170
Total8912