condition mean min max ZT0-3 4.7062608535 3.4673512099999995 5.945170497 ZT4-7 3.4542624774999995 2.5872465934999997 4.321278361499999 ZT8-11 4.09223770525 3.243283951 4.9411914595 ZT12-15 7.50699647975 6.940078088 8.0739148715 ZT16-19 9.635978071 9.3423850605 9.9295710815 ZT20-23 8.05639376375 7.739307607000001 8.3734799205