condition mean min max ZT0-3 11.620658 11.620658 11.620658 ZT4-7 13.910266 13.910266 13.910266 ZT8-11 12.531808000000002 12.531808000000002 12.531808000000002 ZT12-15 12.2595715 12.2595715 12.2595715 ZT16-19 12.8116205 12.8116205 12.8116205 ZT20-23 14.4192155 14.4192155 14.4192155