condition mean min max ZT0-3 2.3395650000000003 2.316315 2.3628150000000003 ZT4-7 2.0848500000000003 2.0848500000000003 2.0848500000000003 ZT8-11 2.826975 2.826975 2.826975 ZT12-15 0 0 0 ZT16-19 3.4849249999999996 3.4849249999999996 3.4849249999999996 ZT20-23 2.7934 2.7934 2.7934