condition mean min max ZT0-3 13.2 13.2 13.2 ZT4-7 7.2 7.2 7.2 ZT8-11 8.35 8.35 8.35 ZT12-15 8.95 8.95 8.95 ZT16-19 5.05 5.05 5.05 ZT20-23 20.349999999999998 20.349999999999998 20.349999999999998