condition mean min max ZT0-3 6.69174 5.5700199999999995 7.813460000000001 ZT4-7 7.09877 7.09877 7.09877 ZT8-11 9.365985 9.365985 9.365985 ZT12-15 0 0 0 ZT16-19 10.367564999999999 10.367564999999999 10.367564999999999 ZT20-23 8.279865000000001 8.279865000000001 8.279865000000001