It looks like the author of that article doesn't know how to write properly lol. However I'm pretty sure he is simply trying to say "the past year" since all years begin in January

The sentence is fine. 'The year to last January' means the twelve-month period from January 2013 to January 2014.

It makes sense, though it is not entirely clear. "the year to" means "the year up to" ie in this case the 12 months ending last January. The previous year is the 12 months before that. What's perhaps not quite clear is whether they mean the beginning of January or the end of January. It would have been better to say "in the year up to the end of December/January than in the previous year". Of course if they mean up to the end of December, it would be better and easier to refer to the year itself ie 2014.