condition mean min max ZT0-3 2.7225125 2.4399550000000003 3.00507 ZT4-7 0.5436059 0.5436059 0.5436059 ZT8-11 1.4858475 1.4858475 1.4858475 ZT12-15 0 0 0 ZT16-19 2.3985600000000002 2.3985600000000002 2.3985600000000002 ZT20-23 2.638535 2.638535 2.638535