condition mean min max ZT0-3 10.820087 10.820087 10.820087 ZT4-7 13.580881 13.580881 13.580881 ZT8-11 11.115664500000001 11.115664500000001 11.115664500000001 ZT12-15 11.2480195 11.2480195 11.2480195 ZT16-19 15.650307999999999 15.650307999999999 15.650307999999999 ZT20-23 13.5912755 13.5912755 13.5912755