condition mean min max ZT0-3 2.66026 2.66026 2.66026 ZT4-7 2.37996 2.37996 2.37996 ZT8-11 2.8110150000000003 2.8110150000000003 2.8110150000000003 ZT12-15 2.474775 2.474775 2.474775 ZT16-19 3.23918 3.23918 3.23918 ZT20-23 2.766655 2.766655 2.766655