condition mean min max ZT0-3 10.1547975 9.951365 10.35823 ZT4-7 7.10496 7.10496 7.10496 ZT8-11 6.072115 6.072115 6.072115 ZT12-15 0 0 0 ZT16-19 8.69646 8.69646 8.69646 ZT20-23 8.08184 8.08184 8.08184