condition mean min max ZT0-3 19.91405 17.93965 21.88845 ZT4-7 11.38335 11.38335 11.38335 ZT8-11 12.76425 12.76425 12.76425 ZT12-15 0 0 0 ZT16-19 19.80735 19.80735 19.80735 ZT20-23 19.8429 19.8429 19.8429