condition mean min max ZT0-3 12.25 12.25 12.25 ZT4-7 6.3 6.3 6.3 ZT8-11 19.200000000000003 19.200000000000003 19.200000000000003 ZT12-15 10.5 10.5 10.5 ZT16-19 27.0 27.0 27.0 ZT20-23 20.1 20.1 20.1