condition mean min max ZT0-3 2.27836 2.27836 2.27836 ZT4-7 1.841815 1.841815 1.841815 ZT8-11 1.86464 1.86464 1.86464 ZT12-15 2.3200950000000002 2.3200950000000002 2.3200950000000002 ZT16-19 2.60777 2.60777 2.60777 ZT20-23 2.42217 2.42217 2.42217