condition mean min max ZT0-3 1.2526971666666669 1.0054115000000001 1.4761950000000001 ZT4-7 1.923775 1.923775 1.923775 ZT8-11 0.8093295 0.8093295 0.8093295 ZT12-15 0.8895007500000001 0.6708935 1.108108 ZT16-19 1.1730445 1.1730445 1.1730445 ZT20-23 1.006586 1.006586 1.006586