condition mean min max ZT0-3 16.526325 14.8251 18.22755 ZT4-7 11.64395 11.64395 11.64395 ZT8-11 12.66545 12.66545 12.66545 ZT12-15 0 0 0 ZT16-19 17.99605 17.99605 17.99605 ZT20-23 14.75085 14.75085 14.75085