condition mean min max ZT0-3 18.22605 18.22605 18.22605 ZT4-7 13.2965 13.2965 13.2965 ZT8-11 10.075235 10.075235 10.075235 ZT12-15 12.017 12.017 12.017 ZT16-19 14.685500000000001 14.685500000000001 14.685500000000001 ZT20-23 17.8624 17.8624 17.8624