*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19880
19890
19900
19914
19924
199323
19946
199510
19960
19974
19981
19990
20000
20010
20022
20031
200410
200519
20060
20070
20080
20090
20101
20110
20120
20132
20140
20154
20160
20170
Total92