*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
19910
19920
19930
19940
19950
19960
19970
19980
19990
20000
20010
20020
2003339
2004307
2005246
20067
200715
20083
200959
20101
20110
20122
20131
201413
201517
201618
201728
20180
Total1056