condition mean min max ZT0-3 12.449143 12.449143 12.449143 ZT4-7 9.4205455 9.4205455 9.4205455 ZT8-11 10.9203435 10.9203435 10.9203435 ZT12-15 11.101251999999999 11.101251999999999 11.101251999999999 ZT16-19 9.8852305 9.8852305 9.8852305 ZT20-23 11.268676 11.268676 11.268676