condition mean min max ZT0-3 5.6493925 4.121335 7.17745 ZT4-7 3.5724549999999997 3.5724549999999997 3.5724549999999997 ZT8-11 4.286885 4.286885 4.286885 ZT12-15 0 0 0 ZT16-19 4.44466 4.44466 4.44466 ZT20-23 6.986935 6.986935 6.986935