condition mean min max ZT0-3 15.842749999999999 15.842749999999999 15.842749999999999 ZT4-7 16.47175 16.47175 16.47175 ZT8-11 7.393075 7.393075 7.393075 ZT12-15 6.0485050000000005 6.0485050000000005 6.0485050000000005 ZT16-19 14.3003 14.3003 14.3003 ZT20-23 15.15635 15.15635 15.15635