condition mean min max ZT0-3 3.6999999999999997 3.6999999999999997 3.6999999999999997 ZT4-7 23.0 23.0 23.0 ZT8-11 10.350000000000001 10.350000000000001 10.350000000000001 ZT12-15 13.25 13.25 13.25 ZT16-19 8.0 8.0 8.0 ZT20-23 19.349999999999998 19.349999999999998 19.349999999999998