condition mean min max ZT0-3 12.697215 12.697215 12.697215 ZT4-7 12.9023885 12.9023885 12.9023885 ZT8-11 13.4714595 13.4714595 13.4714595 ZT12-15 13.209281 13.209281 13.209281 ZT16-19 12.357423 12.357423 12.357423 ZT20-23 13.4662095 13.4662095 13.4662095