condition mean min max ZT0-3 14.975325 14.059999999999999 15.89065 ZT4-7 15.19885 15.19885 15.19885 ZT8-11 16.8624 16.8624 16.8624 ZT12-15 0 0 0 ZT16-19 19.20665 19.20665 19.20665 ZT20-23 16.14405 16.14405 16.14405