*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
199158
199258
19930
199474
199570
199682
1997118
1998155
1999258
2000130
2001164
2002147
2003207
2004289
2005171
2006111
2007851
2008425
2009671
2010642
2011621
2012443
2013567
20140
20150
20160
20170
Total6312