condition mean min max ZT0-3 25.205434 25.205434 25.205434 ZT4-7 22.958064 22.958064 22.958064 ZT8-11 18.485277500000002 18.485277500000002 18.485277500000002 ZT12-15 19.5388825 19.5388825 19.5388825 ZT16-19 20.7876355 20.7876355 20.7876355 ZT20-23 19.334104 19.334104 19.334104