The table shows the annual gross income and the total income tax paid by individuals in a newly formed economy at different income thresholds.
| Annual Gross Income | Total Income Tax Paid |
|---|---|
| £25,000 | £2,000 |
| £35,000 | £3,500 |
| £45,000 | £6,000 |
| £65,000 | £13,000 |
| £85,000 | £22,000 |
What is the marginal tax rate when an individual's annual gross income increases from £45,000 to £65,000?
20.0%20.0\%20.0%
35.0%35.0\%35.0%
45.0%45.0\%45.0%
70.0%70.0\%70.0%
