*Excludes Observations that spanned multiple years

Pre 19707
19700
19710
19720
19730
19740
19750
19761
19771
19780
19790
19801
19810
19820
19832
19840
19852
19860
19871
19880
19890
19901
19912
19921
19931
19940
19951
19961
19970
19980
19990
20000
20010
20021
20030
20040
20050
20060
20071
20080
20090
20100
20110
20121
20130
20140
20150
20160
20172
20180
Total27