condition mean min max ZT0-3 3.1857975 2.79155 3.580045 ZT4-7 7.097994999999999 7.097994999999999 7.097994999999999 ZT8-11 7.868635 7.868635 7.868635 ZT12-15 0 0 0 ZT16-19 5.250125000000001 5.250125000000001 5.250125000000001 ZT20-23 4.03478 4.03478 4.03478