condition mean min max ZT0-3 15.566616 15.566616 15.566616 ZT4-7 20.3933775 20.3933775 20.3933775 ZT8-11 20.6098355 20.6098355 20.6098355 ZT12-15 24.4824455 24.4824455 24.4824455 ZT16-19 19.236492499999997 19.236492499999997 19.236492499999997 ZT20-23 31.017062499999998 31.017062499999998 31.017062499999998