If the money paid in was paid in at the same rate over 17 years the amount paid in would be £6200 x17/10= £10540 (an increase of £4350).
The tax position is less clear. If your figures are exact figures I can't see how the £2000 relates exactly to the £6200. If we assume tax is paid at the same rate the tax will also increase by a factor of 17/10 from £2000 to £3400.
However as the tax rate seems to be more than 20% I think some of your income may have been taxed at 40%. Therefore it's possible that the additional £4350 will be taxed at 40% (£1740).
So it depends on the tax rates that would apply