condition mean min max ZT0-3 2.1788275 2.111825 2.24583 ZT4-7 2.171753 2.171753 2.171753 ZT8-11 1.432745 1.432745 1.432745 ZT12-15 0 0 0 ZT16-19 2.20794 2.20794 2.20794 ZT20-23 3.12334 3.12334 3.12334