condition mean min max ZT0-3 2.512705 2.512705 2.512705 ZT4-7 1.2259950000000002 1.2259950000000002 1.2259950000000002 ZT8-11 0.5705884999999999 0.5705884999999999 0.5705884999999999 ZT12-15 0.679451 0.679451 0.679451 ZT16-19 1.83511 1.83511 1.83511 ZT20-23 3.75146 3.75146 3.75146