i can answer it---in 2000 i bought a property for 125k found a tenant who paid 120pw that rent stayed the sametill 2006 when i did a renovation fitting out the bathroom with rails ect and putting in ramps rent is now 200pw 30% below market value and the property is worth 400k same tenant only she is getting on a bit---property has doubled rent has doubled(well it should have),now this might not happen like this everywhere and it is hard to know an exact time frame and i know of cases where property has fallen in value as i have pointed out ,but here is a clear example of double rent double price