*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
198420
19850
19865
19875
198810
198912
199059
199122
199226
199315
19942
199511
199612
19979
19983
199934
200032
200118
200211
20032
20042
20051
20060
20071
20080
20091
20100
20110
20121
20131
20140
20152
20163
20171
20180
Total321