condition mean min max ZT0-3 2.4066725 2.112545 2.7008 ZT4-7 3.046945 3.046945 3.046945 ZT8-11 4.022460000000001 4.022460000000001 4.022460000000001 ZT12-15 0 0 0 ZT16-19 4.620665000000001 4.620665000000001 4.620665000000001 ZT20-23 5.10959 5.10959 5.10959