When do I have to change the timing belt? clio 1.2, bj.1997

Hello, wanted to ask when I have to change the timing belt at a clio 1.2 , 54 ps, bj.1997? the previous owner changed the timing belt at about 70tkm in 2003. now he has about 160tkm on it. and what would the fun cost me? installation + timing belt + water pump? thank you already in advance.