condition mean min max ZT0-3 10.474635 10.474635 10.474635 ZT4-7 9.91624 9.91624 9.91624 ZT8-11 7.14755 7.14755 7.14755 ZT12-15 6.600275 6.600275 6.600275 ZT16-19 8.676095 8.676095 8.676095 ZT20-23 9.57396 9.57396 9.57396