condition mean min max ZT0-3 135.994466 135.994466 135.994466 ZT4-7 131.362355 131.362355 131.362355 ZT8-11 137.287033 137.287033 137.287033 ZT12-15 157.350467 157.350467 157.350467 ZT16-19 159.4064375 159.4064375 159.4064375 ZT20-23 133.925536 133.925536 133.925536