*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19811
19820
19831
19844
198518
198610
19877
198829
1989117
199022
199151
19925
199393
199453
199515
199655
199730
199812
19994
200021
20011
20025
200333
200439
200544
200626
200731
200834
200930
201037
201132
201239
201332
201446
201544
201629
201728
20180
Total1079