*Excludes Observations that spanned multiple years

Pre 19702
19700
19710
19722
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19871
19880
19890
19900
19915
19923
19934
19941
199527
199615
199724
199823
199920
20000
20010
20020
20031
20040
200513
20061
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total143