condition mean min max ZT0-3 0.4095936666666667 0.4095936666666667 0.4095936666666667 ZT4-7 0.7054674999999999 0.7054674999999999 0.7054674999999999 ZT8-11 0.6495500000000001 0.6495500000000001 0.6495500000000001 ZT12-15 0.394296 0.394296 0.394296 ZT16-19 0.534583 0.534583 0.534583 ZT20-23 1.285917 1.285917 1.285917