The British colonists in America complained about taxation, but how much were they taxed relative to their counterparts in England?

6% instead of 4%

Explanation:

In 1765, the average amount of tax paid by someone in Great Britain itself was 312 pence (26 shillings) per year.

In Massachusetts, Pennsylvania and New York, the average tax was 12 pence per year, or 4% of the amount paid by people in Britain. People in Virginia only paid 5 pence, or less than half that amount.

In the years between 1765 and 1775 Britain greatly increased the tax burden on the American colonists by raising customs duties. This increased the tax burden by a massive 8 pence per head, to 20 pence per year - or 6% of the taxes that people in Britain itself had to pay, rather than 4%. This injustice drove the American patriots to rebellion.

Source: Palmer, R R: The Age of the Democratic Revolution (1959), Princeton University Press