Overall UK GCSE pass rates have fallen this year amid the biggest shake-up of exams in a generation.

Among 16-year-olds in England, around 18,600 maths entries scored a 9 - the new highest grade - while almost 31,000 achieved the top mark in the two English GCSEs combined.

Under the overhaul, traditional A* to G grades are being gradually replaced in England with a 9 to 1 system.

English and maths - key GCSEs for all teenagers - are the first to move across, with other subjects following over the next two years.

Today's figures show that across England, Wales and Northern Ireland, the proportion of entries scoring at least an A grade - or a 7 under the new system - has fallen by 0.5 percentage points to 20% compared to last summer, while the percentage gaining a C or above - or a 4 under the new system - is down 0.6 percentage points to 66.3%.

The statistics, published by the Joint Council for Qualifications (JCQ), show that among 16-year-olds in England:

:: In maths, 3.5% of entries - around 18,617 in total - scored a 9

:: In English, 2.6% of entries - around 13, 754 in total - scored a 9

:: In English literature, 3.3% - around 17,187 in total - scored a 9

:: Girls outperformed boys in 9 grades in both English GCSEs, while boys did better in maths at the highest result

Fewer candidates have achieved a 9 compared to the proportion that gained an A* under the traditional A*-G grading system, following the deliberate move to change the system to allow more differentiation, particularly between the brightest candidates.

Last year, 4% of 16-year-olds in England scored an A* in English language, along with 7% in maths.

The grading switch is part of wider reforms designed to make GCSEs more rigorous and challenging.

There are now three top grades - 7, 8 and 9 - compared to two under the old system - A* and A - with A* results now split into 8s and 9s.

Here are the main figures from today's GCSE results:

:: The proportion of entries receiving the top grades (A/7 or above) has fallen to 20%, down 0.5 percentage points on last year. This is the lowest since 2007 when the figure was 19.5%

:: For entries receiving a C/4 grade or above, the figure for 2017 was 66.3%, a drop of 0.6 percentage points on 2016, and the lowest since 2008

:: In the subjects where a new grading system has been introduced, 3.5% of 16-year-olds in England scored the highest grade 9 in maths, 3.3% scored grade 9 in English literature, and 2.6% scored grade 9 in English

:: In English literature, 72.6% of entries got C/4 or above, down from 75.1% last year. In English the figure rose from 60.2% to 62.1%

:: In maths the overall proportion of entries getting C/4 or above dropped from 61% in 2016 to 59.4%

:: The overall gap between girls and boys getting grade C/4 or above has widened since last year. Some 71% of girls got C/4 or higher compared with 61.5% of boys, a gap of 9.5 percentage points. Last year the gap was 8.9 points

:: The overall pass rate is unchanged on 2016. The proportion of entries receiving G/1 or above was 98.4%

:: In total there were 5,443,072 entrants for the exams, up 4% on last year