About time to change the timing belt

I have owned a 2005 Mitsubishi 380 LS for the past 12 months. I purchased the car with 60,000 km on the clock and it has only done 70,000 km even though it's seven year old. The service manual indicates that the timing belt should be changed at five years or 100,000 km. This has not yet been done. I normally do everything by the book, but changing a timing belt that may be in good working order is an expensive exercise. What are the risks in delaying its replacement?

You say you do things by the book, so why not change the belt. The damage that could be caused to the engine should the belt break don't bear thinking about.