condition mean min max ZT0-3 1.87782 1.87782 1.87782 ZT4-7 1.267085 1.267085 1.267085 ZT8-11 1.64638 1.64638 1.64638 ZT12-15 2.1807299999999996 2.1807299999999996 2.1807299999999996 ZT16-19 2.0228200000000003 2.0228200000000003 2.0228200000000003 ZT20-23 2.133025 2.133025 2.133025