*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19951
19961
19971
19980
19992
20000
20010
20020
20039
20040
2005250
20061
20071
20086
20091
2010424
20110
20120
20130
201439
20151
201625
20170
20180
Total762