The payroll survey also doesn't capture the number of self-employed, and so says little about how many people are generating an independent income.

But in a rare interview in 1990 with the Independent newspaper, she said she had no money and no income from her books and was living with her daughter, Olga, in a Shared rented house.

The total amount of tax due is supposed to be roughly independent of whether the income is earned at home or abroad.