condition mean min max ZT0-3 0.059380527 0.0 0.118761054 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0 0.0 0.0 ZT16-19 0.020149424166666666 0.0 0.04029884833333333 ZT20-23 0.0 0.0 0.0