condition mean min max ZT0-3 11.752575 10.99745 12.5077 ZT4-7 8.938 8.938 8.938 ZT8-11 12.68275 12.68275 12.68275 ZT12-15 0 0 0 ZT16-19 18.12115 18.12115 18.12115 ZT20-23 14.57005 14.57005 14.57005