condition mean min max ZT0-3 8.210085 4.86782 11.55235 ZT4-7 1.566632 1.566632 1.566632 ZT8-11 3.386615 3.386615 3.386615 ZT12-15 0 0 0 ZT16-19 3.5542800000000003 3.5542800000000003 3.5542800000000003 ZT20-23 2.368515 2.368515 2.368515