condition mean min max ZT0-3 18.998888195 14.99046905 23.00730734 ZT4-7 23.8087379125 22.782223545 24.83525228 ZT8-11 19.857299745 19.75893216 19.955667329999997 ZT12-15 14.82606991 14.676465685 14.975674134999998 ZT16-19 15.294347882499999 14.554219495 16.03447627 ZT20-23 17.54563196 16.13747991 18.95378401