condition mean min max ZT0-3 8.628246 8.628246 8.628246 ZT4-7 8.596675000000001 8.596675000000001 8.596675000000001 ZT8-11 9.7580195 9.7580195 9.7580195 ZT12-15 9.196109 9.196109 9.196109 ZT16-19 9.3300035 9.3300035 9.3300035 ZT20-23 8.987134000000001 8.987134000000001 8.987134000000001