condition mean min max ZT0-3 6.8709725 6.08389 7.658054999999999 ZT4-7 12.5403 12.5403 12.5403 ZT8-11 11.6471 11.6471 11.6471 ZT12-15 0 0 0 ZT16-19 10.272535 10.272535 10.272535 ZT20-23 10.752015 10.752015 10.752015