condition mean min max ZT0-3 2.5821750000000003 2.57805 2.5863 ZT4-7 2.365925 2.365925 2.365925 ZT8-11 4.154725 4.154725 4.154725 ZT12-15 0 0 0 ZT16-19 3.47476 3.47476 3.47476 ZT20-23 2.507935 2.507935 2.507935