condition mean min max ZT0-3 16.987948 16.987948 16.987948 ZT4-7 28.46811 28.46811 28.46811 ZT8-11 21.4906025 21.4906025 21.4906025 ZT12-15 17.250298 17.250298 17.250298 ZT16-19 17.908863500000002 17.908863500000002 17.908863500000002 ZT20-23 20.0725505 20.0725505 20.0725505