condition mean min max ZT0-3 11.437577 11.437577 11.437577 ZT4-7 12.587678 12.587678 12.587678 ZT8-11 12.907105000000001 12.907105000000001 12.907105000000001 ZT12-15 11.673625000000001 11.673625000000001 11.673625000000001 ZT16-19 12.955346500000001 12.955346500000001 12.955346500000001 ZT20-23 12.602026 12.602026 12.602026