condition mean min max ZT0-3 2.7316350000000003 1.878895 3.164105 ZT4-7 2.213065 2.213065 2.213065 ZT8-11 3.374355 3.374355 3.374355 ZT12-15 6.177235 5.750495 6.603975 ZT16-19 4.94034 4.94034 4.94034 ZT20-23 5.1391849999999994 5.1391849999999994 5.1391849999999994