condition mean min max ZT0-3 1.954775 1.8824450000000001 2.01999 ZT4-7 1.46187 1.46187 1.46187 ZT8-11 1.757155 1.757155 1.757155 ZT12-15 2.7592975 2.6586800000000004 2.859915 ZT16-19 2.113355 2.113355 2.113355 ZT20-23 2.63091 2.63091 2.63091