condition mean min max ZT0-3 4.665945000000001 4.37119 4.9607 ZT4-7 5.408645 5.408645 5.408645 ZT8-11 6.41756 6.41756 6.41756 ZT12-15 0 0 0 ZT16-19 6.673805 6.673805 6.673805 ZT20-23 7.317905 7.317905 7.317905