condition mean min max ZT0-3 3.8 3.8 3.8 ZT4-7 20.0 20.0 20.0 ZT8-11 11.549999999999999 11.549999999999999 11.549999999999999 ZT12-15 14.2 14.2 14.2 ZT16-19 11.200000000000001 11.200000000000001 11.200000000000001 ZT20-23 13.45 13.45 13.45