condition mean min max ZT0-3 7.481962500000001 6.857570000000001 8.106355 ZT4-7 4.50148 4.50148 4.50148 ZT8-11 4.337315 4.337315 4.337315 ZT12-15 0 0 0 ZT16-19 9.52914 9.52914 9.52914 ZT20-23 7.36878 7.36878 7.36878