condition mean min max ZT0-3 0.3450551666666667 0.3205705 0.370064 ZT4-7 0.07298905 0.07298905 0.07298905 ZT8-11 0.2259805 0.2259805 0.2259805 ZT12-15 0.35419350000000005 0.3188395 0.38954750000000005 ZT16-19 0.3938605 0.3938605 0.3938605 ZT20-23 0.284203 0.284203 0.284203