How do you count bicycles?

Does wall art count or does it have to be ridden to count as a bike?
Does it have to be rideable, whether it's actually used or not, to count?
Does it have to be completely assembled to count?
If you have a frame and all of the necessary parts in boxes, does that count as a bike?
If you share a wheel set between two different bikes, how do you count that?
If you have 2 different bikes that are each 50% complete, does that count as 1 bike?
How about trikes? Should a recumbent trike count as a bike, 1 1/2 bikes (it has 3 wheels) or not a bike?

Once at a party somebody asked me how many bikes I had. While I was considering the above questions in my head my wife opined "He has 8 bicycles." That caused me to wonder which ones she didn't know about.