But it comes on the back of a 14 per cent hike in 2003-4 that angered some education unions dealing with staff redundancies. Geraint Davies, secretary of teachers' union the NASUWT Cymru, said poverty-pleading schools that saved for a rainy day were their own worst enemies.
He said the fall this year was probably down to workload issues, new initiatives such as the learning pathways 14-19 curriculum reforms, and falling pupil rolls.
"The money passed on to schools is supposed to be for current pupils and staff," said Mr Davies. "When I represent teachers being made redundant at schools with huge cash reserves, I have a problem. I am delighted the amount of reserves has come down, but at pound;72m it is still huge."
The figures show that 1,653 out of 1,855 schools had cash reserves in 2005-6, with 360 in excess of 10 per cent - almost double the Wales Audit Office recommended level of 5.1 per cent.
An Assembly government spokesperson said the average school has 4.4 per cent of its delegated budget in reserve. But officials will be strengthening guidance for LEAS on clawing back excess uncommitted funds.
He added: "Unless excessive balances are being held to fund development in school provision, they tie up resources given to benefit pupils and improve outcomes."
Schools are permitted to hold reserves for contingencies, with many heads saying that worries over the funding of new initiatives had forced them to hold back more than they should have done.
But Gareth Jones, secretary of the Association of School and College Leaders Cymru, said the figures only accounted for spent cash up to March 31, 2006 - six months before the end of the school financial year. He said some schools might have bigger reserves because they were saving for equipment such as a new IT suite.
"A drop in cash reserves this year is probably down to 1 per cent efficiency savings being passed on to schools," he added.
The figures show the schools with deficits, totalling pound;5.5m, were broken up into 158 primaries, 39 secondaries and five special schools.
Welsh primaries make up 62 per cent of the surplus.
The figures show the county with the biggest reserves in schools was Conwy, at 8.2 per cent, similar to 2004-5. Monmouthshire schools had the lowest, at 0.8 per cent. Schools in Torfaen have spent more of their reserves this year, up 2.3 per cent on last year.