condition mean min max ZT0-3 1.66469 1.66469 1.66469 ZT4-7 0.823794 0.823794 0.823794 ZT8-11 1.131912 1.131912 1.131912 ZT12-15 1.384525 1.384525 1.384525 ZT16-19 1.8994900000000001 1.8994900000000001 1.8994900000000001 ZT20-23 1.806735 1.806735 1.806735