condition mean min max ZT0-3 6.9368099999999995 6.73762 7.136 ZT4-7 3.84659 3.84659 3.84659 ZT8-11 3.3877800000000002 3.3877800000000002 3.3877800000000002 ZT12-15 0 0 0 ZT16-19 4.746840000000001 4.746840000000001 4.746840000000001 ZT20-23 5.7983 5.7983 5.7983