It was virtually 50/50 and should not have proceeded. The bar to leave was set too low. 2/3rd better, and larger turnout should have been mandated. 16 year olds should have voted. The campaign to stay too weak. Mass confusion. Some particularly pernicious lies on the leave side too convincing. Brexit wasn't 100% going to happen, it was more like...
Leave 17,410,742 51.89% Remain 16,141,241 48.11%