condition mean min max ZT0-3 9.756126666666667 8.0266 11.3493 ZT4-7 7.88677 7.88677 7.88677 ZT8-11 8.975565 8.975565 8.975565 ZT12-15 15.299375000000001 13.20465 17.3941 ZT16-19 13.16465 13.16465 13.16465 ZT20-23 15.1054 15.1054 15.1054