Factcheck: How many wildfires resulted from managed burns escaping control?

What The Science Says website checks out another claim:

Claim: 68% of wildfires in the higher uplands have been caused by so-called controlled cold fires.

This came from a recent Westminster moorland burning debate, in relation to tackling climate change and carbon release, Olivia Blake MP (Sheffield, Hallam, Labour) discussed multiple statistics about burning, including:

Is the hon. Member aware of some the most recent research, which shows that 68% of wildfires in the higher uplands have actually been caused by so-called controlled cold fires? Olivia Blake MP

Read the answer here