condition mean min max ZT0-3 9.38502 9.38502 9.38502 ZT4-7 6.4115850000000005 6.4115850000000005 6.4115850000000005 ZT8-11 4.880915 4.880915 4.880915 ZT12-15 7.28772 7.28772 7.28772 ZT16-19 8.437380000000001 8.437380000000001 8.437380000000001 ZT20-23 5.88687 5.88687 5.88687