Michael Percy wrote in message
...
Jim Webster wrote:

a fine summer in the SE and you could get up as high as 20

Sure, I'd say in a fine summer (warm, sunny) you could get potential
transpiration rates rather higher than that in south england!

and as I also said, and you snipped

"if the figure was important someone would probably publish the
figures"


--
Jim Webster

"The pasture of stupidity is unwholesome to mankind"

'Abd-ar-Rahman b. Muhammad b. Khaldun al-Hadrami'