condition mean min max ZT0-3 5.2602275 5.142495 5.37796 ZT4-7 4.135725 4.135725 4.135725 ZT8-11 6.0239650000000005 6.0239650000000005 6.0239650000000005 ZT12-15 0 0 0 ZT16-19 7.473545 7.473545 7.473545 ZT20-23 7.146005000000001 7.146005000000001 7.146005000000001