condition mean min max ZT0-3 3.3825525 2.917125 3.8479799999999997 ZT4-7 1.798095 1.798095 1.798095 ZT8-11 2.43035 2.43035 2.43035 ZT12-15 0 0 0 ZT16-19 2.78072 2.78072 2.78072 ZT20-23 4.03501 4.03501 4.03501