condition mean min max ZT0-3 8.046775 8.046775 8.046775 ZT4-7 8.7639545 8.7639545 8.7639545 ZT8-11 6.8047205 6.8047205 6.8047205 ZT12-15 8.2250115 8.2250115 8.2250115 ZT16-19 7.7109755 7.7109755 7.7109755 ZT20-23 7.7750140000000005 7.7750140000000005 7.7750140000000005