*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
19923
19932
19943
199534
19960
19971
199812
19991
20001
20011
20020
20030
20040
20056
20061
20071
20082
20090
20100
20115
20120
20130
20140
20150
20162
20170
Total75