The practice earnings to expenses ratio hit 62.6% in 2014/15, up 0.7 percentage points from the previous financial year and up 8.2 percentage points from 54.2% in 2005/6 - the second full year of the 2004 GMS contract.
In cash terms, according to data published by NHS Digital, GP partners across GMS and PMS contracts saw pay rise by 1.7% between 2013/14 and 2014/15, with income up from £99,800 to £101,500. But in real terms - taking into account inflation - the increase is negligible, with pay going up from £101,400 to £101,500.
Over the past decade, GP partners' income has remained flat in cash terms but fallen sharply in real terms. Partners on GMS and PMS contracts earned an average of £100,170 in 2004/5, equivalent to £122,982 in real terms today - a staggering 21% more than the £101,500 they earned in 2014/15.
Salaried GPs saw their pay fall in 2014/15 to an average of £53,600, down from £54,600 in 2013/14 - a 1.7% fall. Median pay for salaried GPs was £50,300, down from £51,200.
In real terms, salaried GP pay fell by £1,800 from 2013/14 to 2014/15. Since 2006/7, it has fallen sharply - down 14.3% from £62,604, although because the data include income details from both full-time and part-time GPs, the decrease could reflect a rise in part-time working.
The data show that GMS partners' income rose faster in cash terms in 2014/15 than PMS partners' income - GMS average income rose from £96,000 to £98,000, while PMS partners' income rose from £106,800 to £108,000.
The figures also show the gulf in pay that remains between GPs in different parts of the UK, and within England.
Partners' average income across GMS and PMS contracts is £103,800 in England, but just £90,700 in Wales. In Northern Ireland the figure is £98,500, and in Scotland £91,400.
Partners in the South East region have the highest income in England, with £108,600 before tax in 2014/15. In the South West region of England, by contrast, average income before tax is just £84,500 - 22% lower.
GPC deputy chairman Dr Richard Vautrey told GPonline: 'The continued rise in the earnings to expenses ratio to now unprecedented levels is a sign of the massive pressure general practice is now under.
'The biggest expense practices have is their staff and these figures suggest that GPs are putting their staff first and ensuring they receive the pay increases they deserve even if that comes at the personal expense to the GPs' own income.
'This report provides clear justification for the urgent need to significantly invest in core general practice for a failure to do so will undoubtedly just fuel the GP recruitment and retention crisis.'