condition mean min max ZT0-3 23.728932 23.728932 23.728932 ZT4-7 16.980674999999998 16.980674999999998 16.980674999999998 ZT8-11 20.2100035 20.2100035 20.2100035 ZT12-15 14.5644 14.5644 14.5644 ZT16-19 17.7908295 17.7908295 17.7908295 ZT20-23 13.221619 13.221619 13.221619