condition mean min max ZT0-3 1.6006508333333334 0.7797925 2.3344750000000003 ZT4-7 1.536635 1.536635 1.536635 ZT8-11 4.20818 4.20818 4.20818 ZT12-15 2.443985 2.1918550000000003 2.696115 ZT16-19 3.363765 3.363765 3.363765 ZT20-23 2.9340200000000003 2.9340200000000003 2.9340200000000003