condition mean min max ZT0-3 11.271512 11.271512 11.271512 ZT4-7 9.272263500000001 9.272263500000001 9.272263500000001 ZT8-11 10.7226725 10.7226725 10.7226725 ZT12-15 10.737129 10.737129 10.737129 ZT16-19 12.250486 12.250486 12.250486 ZT20-23 12.0229555 12.0229555 12.0229555