condition mean min max ZT0-3 39.172675 30.19565 48.149699999999996 ZT4-7 22.5527 22.5527 22.5527 ZT8-11 16.4927 16.4927 16.4927 ZT12-15 0 0 0 ZT16-19 36.114599999999996 36.114599999999996 36.114599999999996 ZT20-23 49.03365 49.03365 49.03365