condition mean min max ZT0-3 12.589391666666668 6.844575 16.4099 ZT4-7 5.2856950000000005 5.2856950000000005 5.2856950000000005 ZT8-11 5.91419 5.91419 5.91419 ZT12-15 8.612355 7.654745 9.569965 ZT16-19 14.6934 14.6934 14.6934 ZT20-23 21.01575 21.01575 21.01575