condition mean min max ZT0-3 3.15061 2.903905 3.397315 ZT4-7 1.894555 1.894555 1.894555 ZT8-11 3.25494 3.25494 3.25494 ZT12-15 0 0 0 ZT16-19 8.414670000000001 8.414670000000001 8.414670000000001 ZT20-23 7.004825 7.004825 7.004825