Comment by salaryFoo

As another data-point: My day-rates as a long-term contractor which have some decent year-on-year increases from switching clients

2012 £200 (first time programming for money)

2013 £300 (new client)

2014 £425 (new client)

2015 - took a year off -

2016 £500 (new client)

2017 £650 (same client)

2018 £800 (new client)