condition mean min max ZT0-3 0.0830558 0.0830558 0.0830558 ZT4-7 0.0386959 0.0386959 0.0386959 ZT8-11 0.0140325 0.0140325 0.0140325 ZT12-15 0.046743849999999997 0.046743849999999997 0.046743849999999997 ZT16-19 0.09012385 0.09012385 0.09012385 ZT20-23 0.07807420000000001 0.07807420000000001 0.07807420000000001