*Excludes Observations that spanned multiple years

Pre 19700
19702
19711
19727
19730
19741
19750
19761
19771
19781
19790
19800
19810
19822
19832
19844
19853
198646
198731
198856
198953
199025
199172
199242
19939
199415
199525
199615
199732
199816
199933
200040
200148
200212
200318
200416
200521
20068
20077
20087
200910
201020
201116
201212
20139
20149
201512
201612
20178
20180
20190
Total780