*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19755
19767
19770
19786
19794
19803
19813
19828
198327
198412
198521
19869
19879
19888
19893
19904
199168
19928
199370
1994154
1995174
1996186
1997452
1998281
1999544
2000205
2001272
2002203
2003289
2004405
2005321
2006294
2007965
2008409
2009689
2010901
2011450
2012482
2013414
201410
20150
20162
20170
Total8377