Like others, it depends. I have had LW3 for 10 years and finally decided to try and sell it recently. I have had up to 19 at one time but usually have 14. Tommy made it 5 years. JD 4 years. Miss them both. Acdc(Luci) and Pinball Magic will never leave..ever! Lol. I could see JM and Maverick leaving soon. Had them for 5 years. I think my average time is 4-5 years now that you got my brain thinking about it