condition mean min max ZT0-3 1.99391 1.99391 1.99391 ZT4-7 1.934025 1.934025 1.934025 ZT8-11 1.64768 1.64768 1.64768 ZT12-15 1.7060149999999998 1.7060149999999998 1.7060149999999998 ZT16-19 2.687955 2.687955 2.687955 ZT20-23 2.00033 2.00033 2.00033