Only 18 UK teachers have been struck off for incompetence in the past 40 years, the BBC's Panorama has learned.
Shocking. Altogether shocking, especially when you consider 17,000 teachers might be seen as incompetent.
Though it does bring into question what you define as 'incompetent' - there are about 70 teachers in my school, less than 5% means about 3 of them max, and there's more that I'd consider incompetent than that (in a good school too).
In fact I could probably name 18 that are incompetent.
But then, if we applied those standards, we'd probably have a shortage of teachers.