*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
19888
19890
19900
19910
19920
19938
19943
19950
19965
19979
199841
199956
200041
200115
2002125
2003136
200470
200565
2006108
200786
200883
2009135
2010180
2011129
201236
201386
20141
20150
20160
20170
Total1426