condition mean min max ZT0-3 3.9564174999999997 3.8549749999999996 4.05786 ZT4-7 6.060315 6.060315 6.060315 ZT8-11 6.829505 6.829505 6.829505 ZT12-15 0 0 0 ZT16-19 6.05715 6.05715 6.05715 ZT20-23 6.6025 6.6025 6.6025