condition mean min max ZT0-3 2.0676825 1.893975 2.24139 ZT4-7 2.905395 2.905395 2.905395 ZT8-11 1.7227200000000003 1.7227200000000003 1.7227200000000003 ZT12-15 0 0 0 ZT16-19 3.8077449999999997 3.8077449999999997 3.8077449999999997 ZT20-23 6.408185 6.408185 6.408185