Complex sentence: At the time of its introduction in 1999, the reduced tax rate of 10% applied to incomes between £4,335 and £5,835 and was the only income tax paid by 1.8 million of the lowest earners.
Split into simpler sentences: At the time of its introduction in 1999, the reduced tax rate of 10% applied to incomes between £4,335 and £5,835. The reduced starting rate was the only income tax paid by 1.8 million of the lowest earners.