*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19771
19781
19791
19800
19811
19820
19830
19842
19852
19862
19870
19880
19890
19904
19910
19923
19931
19946
19951
19963
19970
19980
19991
20000
200116
20023
20030
20040
20050
20063
20070
20080
20090
20103
201133
20123
20131
20142
20151
20167
201714
20185
201936
20200
Total156