condition mean min max ZT0-3 2.679445 2.459875 2.899015 ZT4-7 2.42636 2.42636 2.42636 ZT8-11 3.2561 3.2561 3.2561 ZT12-15 0 0 0 ZT16-19 4.77799 4.77799 4.77799 ZT20-23 3.2106500000000002 3.2106500000000002 3.2106500000000002