condition mean min max ZT0-3 11.150892 11.150892 11.150892 ZT4-7 10.930715 10.930715 10.930715 ZT8-11 10.951966500000001 10.951966500000001 10.951966500000001 ZT12-15 9.4354525 9.4354525 9.4354525 ZT16-19 12.813130000000001 12.813130000000001 12.813130000000001 ZT20-23 11.693638 11.693638 11.693638