*Excludes Observations that spanned multiple years

Pre 197016
19700
19710
19720
19731
19740
19751
19760
19770
19780
19791
19801
19811
19820
19830
19840
19850
19860
19870
19882
19890
19901
19910
19920
19931
19940
19950
19961
19970
19980
19990
20000
20010
20020
20030
20041
20050
20060
20071
20080
20091
20100
20110
20120
20130
20141
20150
20160
20170
Total30