condition mean min max ZT0-3 1.8768366666666665 1.8768366666666665 1.8768366666666665 ZT4-7 1.3147535000000001 1.3147535000000001 1.3147535000000001 ZT8-11 0.679728 0.679728 0.679728 ZT12-15 0.809457 0.809457 0.809457 ZT16-19 1.190711 1.190711 1.190711 ZT20-23 1.2024966696000001 1.2024966696000001 1.2024966696000001