Don't know...but I do know that postgrad students at Chester College (when it was a PE Teacher Training College in the 80's)conducted research into referees' movements during a match...with a view to designing a training regime to ensure that referees trained properly. The research involved observing monitoring referees at every Chester FC home game during a season (when they were in 4th Division...a status they have happily regained!!!). The College may be able to look for info in archives or at least point you in right direction.