condition mean min max ZT0-3 18.9834 18.9834 18.9834 ZT4-7 16.4769 16.4769 16.4769 ZT8-11 15.013200000000001 15.013200000000001 15.013200000000001 ZT12-15 17.86265 17.86265 17.86265 ZT16-19 22.72775 22.72775 22.72775 ZT20-23 20.19295 20.19295 20.19295