condition mean min max ZT0-3 8.1668508705 5.934393861 10.39930788 ZT4-7 5.3304665685 4.5866652575 6.0742678795 ZT8-11 6.32719378125 5.739520951499999 6.914866611000001 ZT12-15 7.39265512375 6.085988638 8.6993216095 ZT16-19 9.42790601075 7.959614181499999 10.89619784 ZT20-23 17.110915635 14.83265446 19.389176810000002