condition mean min max ZT0-3 2.687039283 2.570660182 2.8034183839999995 ZT4-7 2.59860111025 2.0688296260000003 3.1283725945 ZT8-11 4.3819769575 3.8779222129999997 4.886031702 ZT12-15 3.2763225815 3.2049258170000003 3.347719346 ZT16-19 4.175852784 3.2346306975 5.1170748705 ZT20-23 5.880576802 5.3558856565 6.4052679475000005