*Excludes Observations that spanned multiple years

Pre 19700
19701
19710
19720
19730
19741
19750
19761
19772
19782
19790
19800
19810
19820
19831
19840
19850
19860
19879
198821
198933
19900
19918
199212
19936
19948
199510
199613
199720
19988
199911
200017
20012
20021
200317
20049
200516
200613
200710
200815
200911
201019
201110
201217
201310
201411
201515
201613
201715
20180
Total388