Heat pump experiment review after two years

Thanks for posting such a detailed study

I’m considering a heat pump for my newbuild
One concern I have is the slow ramp up because of the low temperature output, so the HP has to be operating for longer, leading to greater losses through the insulation

How many kWh of oil per year were used in the years before fitting the HP? To compare with how many kWh post HP fitting. That would give a closer to realworld COP