condition mean min max ZT0-3 21.326217 21.326217 21.326217 ZT4-7 17.9275825 17.9275825 17.9275825 ZT8-11 15.9472685 15.9472685 15.9472685 ZT12-15 15.521089 15.521089 15.521089 ZT16-19 15.1539325 15.1539325 15.1539325 ZT20-23 14.141345000000001 14.141345000000001 14.141345000000001