Difficult question to answer - while it may appear that I build a model a week sometimes, I really work on multiple projects most of the time. Small bits and pieces or assemblies whenever the inspiration strikes. Then I will go back to another project. Eventually, one project gets "chosen" to be finished and that one is done. Some models have been started years ago, others months ago. I know I have some cabs/hoods that were painted in 2004 that I haven't built yet.
Tim