condition mean min max ZT0-3 3.1035925000000004 2.33515 3.8720350000000003 ZT4-7 6.864025 6.864025 6.864025 ZT8-11 3.060195 3.060195 3.060195 ZT12-15 0 0 0 ZT16-19 3.4991450000000004 3.4991450000000004 3.4991450000000004 ZT20-23 4.27654 4.27654 4.27654