condition mean min max ZT0-3 13.021554 13.021554 13.021554 ZT4-7 14.1359445 14.1359445 14.1359445 ZT8-11 15.003911500000001 15.003911500000001 15.003911500000001 ZT12-15 12.867564 12.867564 12.867564 ZT16-19 10.6778165 10.6778165 10.6778165 ZT20-23 11.9263225 11.9263225 11.9263225