condition mean min max ZT0-3 22.794111 22.794111 22.794111 ZT4-7 20.1575085 20.1575085 20.1575085 ZT8-11 29.099066 29.099066 29.099066 ZT12-15 23.543817500000003 23.543817500000003 23.543817500000003 ZT16-19 34.123064 34.123064 34.123064 ZT20-23 26.1565645 26.1565645 26.1565645