condition mean min max ZT0-3 16.6 16.6 16.6 ZT4-7 23.4 23.4 23.4 ZT8-11 9.649999999999999 9.649999999999999 9.649999999999999 ZT12-15 10.8 10.8 10.8 ZT16-19 7.3 7.3 7.3 ZT20-23 11.05 11.05 11.05