condition mean min max ZT0-3 8.726975 8.726975 8.726975 ZT4-7 10.011207500000001 10.011207500000001 10.011207500000001 ZT8-11 10.0754835 10.0754835 10.0754835 ZT12-15 9.196368 9.196368 9.196368 ZT16-19 10.3722615 10.3722615 10.3722615 ZT20-23 9.385934500000001 9.385934500000001 9.385934500000001