Google Maps vs. HERE Maps: How often does Nokia update their maps database?

I find that on my Lumia whenever I search for some local business listings, many times the HERE maps can't find the place while Google Maps does. There is a 2 year old restaurant near my home that still does not show up on HERE.

Questions: How often does Nokia update their maps database? Does Google Maps generally have better database? Can the Nokia HERE maps ever catchup?