condition mean min max ZT0-3 20.484425 18.79925 22.169600000000003 ZT4-7 26.3477 26.3477 26.3477 ZT8-11 34.4417 34.4417 34.4417 ZT12-15 0 0 0 ZT16-19 36.6374 36.6374 36.6374 ZT20-23 25.552500000000002 25.552500000000002 25.552500000000002