condition mean min max ZT0-3 1.532945 1.532945 1.532945 ZT4-7 0.8736548333333334 0.8736548333333334 0.8736548333333334 ZT8-11 0.960558 0.960558 0.960558 ZT12-15 1.415405 1.415405 1.415405 ZT16-19 1.382696 1.382696 1.382696 ZT20-23 1.154554 1.154554 1.154554