*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19751
19760
19770
19780
19790
19801
19810
19820
19830
19840
19853
198610
198737
198825
198929
19902
199148
199215
1993162
199475
199596
199638
199723
199816
19997
200022
200110
200212
20036
20048
20057
200612
20076
20086
20096
20106
20117
201212
201312
20149
201511
201614
20179
20180
20190
20200
Total764