Catherine Johnson from kitchen table math is reporting that the number of students in the USA identified as having a 'specific learning disability' has declined over the past ten years from 6.1% in 2000-2001 to 5.2% in 2007-2008. The figures come from the U.S Department of Education's 2009 Digest of Education Statistics.
As is the case here in UK, about 80% of pupils to whom the classification applies are those struggling with learning to read. This is very similar to the figure arrived at by Dr John Marks ten years ago.
What's the cause for the drop? Are they counting differently or has teaching methodology improved? Speculation has it that its the former.
For the record, kitchen table math is an excellent source of ideas and resources, particularly in respect of how to teach mathematics. However, Catherine Johnson often posts on more general areas of education. Following her recommendation, I'm currently reading Teach Like a Champion: 49 Techniques That Put Students on the Path to College. It's a great, no-nonsense book, full of excellent advice by Doug Lemov, managing director of Uncommon Schools. I'd put it into the hands of every trainee- and practising teacher.