I'm assuming your 71% accurate calculation comes from taking the £75m rebate away from £350m.
But what about the money within that which returns to the UK in farming subsidies, science and university research, helping underdeveloped areas (we in Wales have many of those)? There are loads of EU projects which benefit us that the uk government would absolutely never spend money on, especially in our days (years?) of austerity.
It was a shameful lie and in this Trumpian world, our politicians double down on the lies. Don't be part of the problem because you will suffer just as the rest of us do. The rest of us except for the likes of BOJO.