condition mean min max ZT0-3 16.60458 16.60458 16.60458 ZT4-7 18.38803 18.38803 18.38803 ZT8-11 16.051275 16.051275 16.051275 ZT12-15 15.742743 15.742743 15.742743 ZT16-19 13.814536 13.814536 13.814536 ZT20-23 15.060479 15.060479 15.060479