condition mean min max ZT0-3 4.42553 4.42553 4.42553 ZT4-7 4.99122 4.99122 4.99122 ZT8-11 1.221825 1.221825 1.221825 ZT12-15 1.48661 1.48661 1.48661 ZT16-19 1.284705 1.284705 1.284705 ZT20-23 2.718785 2.718785 2.718785