condition mean min max ZT0-3 18.3772493275 16.909036354999998 19.8454623 ZT4-7 17.6683938375 14.567343325 20.76944435 ZT8-11 21.33633935 18.153171985 24.519506715 ZT12-15 24.50499069 23.392028465 25.617952914999996 ZT16-19 18.605010155000002 17.99801936 19.21200095 ZT20-23 27.307594435000002 24.227234875 30.387953995000004