condition mean min max ZT0-3 26.83835 26.83835 26.83835 ZT4-7 23.4354 23.4354 23.4354 ZT8-11 20.16285 20.16285 20.16285 ZT12-15 17.4836 17.4836 17.4836 ZT16-19 23.3478 23.3478 23.3478 ZT20-23 21.203850000000003 21.203850000000003 21.203850000000003