condition mean min max ZT0-3 0.146837 0.146837 0.146837 ZT4-7 0.13530150000000002 0.13530150000000002 0.13530150000000002 ZT8-11 0.15982400000000002 0.15982400000000002 0.15982400000000002 ZT12-15 0.3209965 0.3209965 0.3209965 ZT16-19 0.4229906666666667 0.4229906666666667 0.4229906666666667 ZT20-23 0.21242640000000002 0.21242640000000002 0.21242640000000002