condition mean min max ZT0-3 10.797581 10.797581 10.797581 ZT4-7 12.128953 12.128953 12.128953 ZT8-11 11.4984755 11.4984755 11.4984755 ZT12-15 12.775316 12.775316 12.775316 ZT16-19 12.554195499999999 12.554195499999999 12.554195499999999 ZT20-23 9.6089375 9.6089375 9.6089375