And sometimes whole periods of data would be missing with no explanation. (slaw.ca)
Using satellite data, and calculating the delta compared to the average monthly values for whole period covered, the resulting annual averages become: 2001 0.163 2002 0.279 2003 0.278 2004 0.178 2005 0.299 2006 0.210 2007 0.088 I.e. 2007 is coldest year in this millenium, century, and decade. (desmogblog.com)
For breeds with a mean of > 50 registrations per annum (in each of the seven 5 - year blocks, n = 121), the mean whole period generation interval ranged from 3.06 years (Miniature Bull Terrier) to 5.04 years (Bearded Collie), with a mean of 3.88 years and standard deviation of 0.412 years. (cgejournal.biomedcentral.com)