condition mean min max ZT0-3 11.4 11.4 11.4 ZT4-7 19.9 19.9 19.9 ZT8-11 11.1 11.1 11.1 ZT12-15 11.649999999999999 11.649999999999999 11.649999999999999 ZT16-19 16.25 16.25 16.25 ZT20-23 8.9 8.9 8.9