*Excludes Observations that spanned multiple years

Pre 19706
19701
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19873
19882
19890
19906
19914
19921
19931
19943
19957
19961
19978
199810
19993
20000
20011
20020
20033
20040
20050
20061
20070
20080
20090
20100
20110
20123
20138
20142
20152
20160
20171
20180
20191
20201
20218
20223
20233
20241
Total95