condition mean min max ZT0-3 6.22296974775 4.6436104245 7.802329071 ZT4-7 4.2175196995 3.6387039585 4.7963354405 ZT8-11 6.2469374935 5.2700498945 7.2238250925 ZT12-15 5.6910128225 5.329098881 6.052926764 ZT16-19 6.000246165749999 5.0548130895 6.945679242 ZT20-23 8.20217362925 8.0105733275 8.393773931