Broker with +12 Month 15m Charts?

Does anyone know of a broker with 15m charts that will provide data beyond 12 months? My back testing is fairly extensive and goes back 3+ years but unfortunately becomes irrelevant beyond 12 months as I am not able to update past results with refinements in my trading methodology.

Thanks,

Rex

In case anybody had the same question, Dukascopy provides 15m charts that extend beyond 1 year. Thank you Dukascopy.