*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19771
19780
19790
19801
19811
19820
19830
19840
19850
19860
19871
19880
19890
19904
19910
19920
19930
19940
19951
19960
19970
19980
19990
20000
20010
20020
20030
20041
20050
20060
20070
20082
20090
20100
20110
20121
20130
20141
20150
20161
20170
20180
20190
20203
20212
20224
20230
20246
Total31