*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19811
19820
19830
19840
19850
19860
19870
198829
19892
19900
19911
19923
19933
19949
19958
19962
19971
199815
19994
20003
20018
20021
20035
20045
20051
20060
20070
20081
20091
20100
20112
20120
20130
20141
20151
20165
20170
20183
Total116