condition mean min max ZT0-3 3.7838716666666667 1.19008 5.137230000000001 ZT4-7 1.31412 1.31412 1.31412 ZT8-11 2.820315 2.820315 2.820315 ZT12-15 7.791345000000001 5.349880000000001 10.23281 ZT16-19 10.656195 10.656195 10.656195 ZT20-23 10.049195 10.049195 10.049195