condition mean min max ZT0-3 13.880201666666666 8.515755 17.0309 ZT4-7 6.396505 6.396505 6.396505 ZT8-11 5.635465 5.635465 5.635465 ZT12-15 10.1345925 9.417035 10.85215 ZT16-19 12.1867 12.1867 12.1867 ZT20-23 20.10135 20.10135 20.10135