Read this and answer the question. If the question is unanswerable, say "unanswerable".

The first satellite of the second-generation system, Compass-M1 was launched in 2007. It was followed by further nine satellites during 2009-2011, achieving functional regional coverage. A total of 16 satellites were launched during this phase.

How many satellites were launched between 2005 and 2007?
unanswerable