condition mean min max ZT0-3 7.790375000000001 7.790375000000001 7.790375000000001 ZT4-7 6.82666 6.82666 6.82666 ZT8-11 5.25234 5.25234 5.25234 ZT12-15 5.637015 5.637015 5.637015 ZT16-19 8.22186 8.22186 8.22186 ZT20-23 6.556699999999999 6.556699999999999 6.556699999999999