condition mean min max ZT0-3 7.35654 7.35654 7.35654 ZT4-7 7.139065 7.139065 7.139065 ZT8-11 6.88095 6.88095 6.88095 ZT12-15 8.90396 8.90396 8.90396 ZT16-19 6.60798 6.60798 6.60798 ZT20-23 7.3276900000000005 7.3276900000000005 7.3276900000000005