condition mean min max ZT0-3 3.92112 2.530305 4.95892 ZT4-7 2.0858350000000003 2.0858350000000003 2.0858350000000003 ZT8-11 2.6941499999999996 2.6941499999999996 2.6941499999999996 ZT12-15 3.9826575 3.7594250000000002 4.20589 ZT16-19 4.5223949999999995 4.5223949999999995 4.5223949999999995 ZT20-23 8.09358 8.09358 8.09358