condition mean min max ZT0-3 2.60584 1.94482 3.337355 ZT4-7 7.667025 7.667025 7.667025 ZT8-11 9.336495 9.336495 9.336495 ZT12-15 7.5090775 7.18541 7.832745000000001 ZT16-19 4.52478 4.52478 4.52478 ZT20-23 3.5667099999999996 3.5667099999999996 3.5667099999999996