*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
19872
19882
19896
19903
19913
19926
19939
19945
19958
19961
199721
19988
19994
20000
20010
20024
20033
20042
200512
20061
20072
20083
20091
20101
20110
20120
20131
20140
20150
20160
20170
Total108