condition mean min max ZT0-3 61.3116611525 50.109289325000006 72.51403298 ZT4-7 6.99924455875 4.4559890865 9.542500031 ZT8-11 7.7373827225 4.571591646 10.903173799 ZT12-15 8.0526521665 7.0027222735 9.1025820595 ZT16-19 9.4935404545 8.2494434825 10.7376374265 ZT20-23 15.74093741 15.464777185 16.017097635