condition mean min max ZT0-3 8.943163 8.943163 8.943163 ZT4-7 10.010315 10.010315 10.010315 ZT8-11 8.9850055 8.9850055 8.9850055 ZT12-15 9.987165000000001 9.987165000000001 9.987165000000001 ZT16-19 9.3961235 9.3961235 9.3961235 ZT20-23 9.9726985 9.9726985 9.9726985