Bills for the period (electricity, gas, credit card, bank statments etc), proof of address, did you have a full or provisional driver's liecense (that would help too).
I'd say that the most reliable source of this information is via the council tax office. I'm not trying to claim that the council tax office is reliable - far from it - just that if you get the information from there, I'd view it as more trustworthy.
I could easily be added onto someone's utility bill without actually living at that address. Also if I ask my bank for copies of statements from 1995, they'll show only my current address where they're posted to rather than where I lived back then.