condition mean min max ZT0-3 5.8152375 5.08098 6.549495 ZT4-7 7.677524999999999 7.677524999999999 7.677524999999999 ZT8-11 7.09052 7.09052 7.09052 ZT12-15 0 0 0 ZT16-19 8.62034 8.62034 8.62034 ZT20-23 7.510115 7.510115 7.510115