condition mean min max ZT0-3 19.873775000000002 18.89255 20.855 ZT4-7 7.823425 7.823425 7.823425 ZT8-11 6.791295 6.791295 6.791295 ZT12-15 0 0 0 ZT16-19 12.3348 12.3348 12.3348 ZT20-23 14.41145 14.41145 14.41145