A TES analysis reveals that 92.1 per cent of students who took an AS-level in Welsh in 2003 chose to continue the course to A-level this year. This staying-on rate is higher than that for every other subject, apart from minority foreign languages, such as Russian, Punjabi and Polish, which are grouped together.
The figures, based on entries to 32 subjects, also show a link between drop-out rates and high failure rates at AS. In 2003, Welsh AS had a 99.1 per cent pass rate: higher than any other subject.
But Neil Foden, head of Ysgol Friars, in Bangor, does not believe that the high pass-rate alone accounts for the subject's low number of drop-outs.
He said: "Wales is now a separate political entity. More people are aware of careers that enable them to stay in Wales, and for which Welsh is a useful additional qualification."
Since devolution in 1999, many Welsh-speaking jobs have been created, both in the Welsh Assembly and the Welsh media, and there is increased competition for Welsh-speaking graduates. Devolution has also made many young people more aware of their cultural heritage.
A spokeswoman for the Welsh Language Board said: "Once pupils get to grips with the subject at GCSE level, they see that it's a part of their fabric, an inherent part of who they are.
"The Welsh language inevitably plays a large part in their sense of identity. For some of them, it is a source of inspiration. So they realise its importance as a subject."