condition mean min max ZT0-3 13.9365722745 11.930941199 15.94220335 ZT4-7 7.371557674500001 7.053969761500001 7.6891455875000005 ZT8-11 6.191860812750001 6.1822649080000005 6.2014567175 ZT12-15 3.85622513825 3.388036026 4.3244142505 ZT16-19 4.580571417750001 3.2789506514999998 5.882192184000001 ZT20-23 14.614109006 10.317853891999999 18.91036412