condition mean min max ZT0-3 9.212936 9.212936 9.212936 ZT4-7 9.785761 9.785761 9.785761 ZT8-11 9.350873 9.350873 9.350873 ZT12-15 9.0422815 9.0422815 9.0422815 ZT16-19 9.097761 9.097761 9.097761 ZT20-23 9.5635745 9.5635745 9.5635745