*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19723
19731
19740
19751
19760
19770
19780
19790
19800
19810
19820
19830
198418
198531
198633
198731
198859
198982
199063
199125
199219
199315
19942
19950
19964
199711
199817
199925
200044
20018
20026
20033
20047
20051
20062
20076
20085
20094
20104
20117
20124
20135
20145
201511
201612
201713
20180
20190
Total588