£100,000 in 2003 is the equivalent of £150,307.61 in 2017, and probably more in 2018. You would need to be on over £150k a year to meet your £100k a year goal from 2003 in terms of buying power.
The good news is if you don't get any pay cuts against inflation, and the average rate of inflation stays the same, then you will be on £100k in ten years without receiving a pay increase.
Source: https://www.bankofengland.co.uk/monetary-policy/inflation/inflation-calculator
Looks like i'll have to extend my goal then! I guess the 100K is just an arbitrary number, once i hit that i will be looking for the next step anyway.