condition mean min max ZT0-3 22.4554 22.4554 22.4554 ZT4-7 15.3431 15.3431 15.3431 ZT8-11 11.5292 11.5292 11.5292 ZT12-15 20.99855 20.99855 20.99855 ZT16-19 18.3624 18.3624 18.3624 ZT20-23 23.90095 23.90095 23.90095