*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19872
19880
19891
19900
19910
19920
19930
19948
199513
19962
19970
19980
19994
200076
20010
20020
20030
200436
20058
200666
2007145
200848
2009104
2010238
2011250
2012124
2013139
20140
Total1265