condition mean min max ZT0-3 0.286346 0.251526 0.326928 ZT4-7 0.3809445 0.3809445 0.3809445 ZT8-11 0.603524 0.603524 0.603524 ZT12-15 3.2996125000000003 3.1661200000000003 3.4331050000000003 ZT16-19 1.31627 1.31627 1.31627 ZT20-23 0.8267534999999999 0.8267534999999999 0.8267534999999999