condition mean min max ZT0-3 7.0989275 7.0784199999999995 7.119435 ZT4-7 5.9662749999999996 5.9662749999999996 5.9662749999999996 ZT8-11 4.996755 4.996755 4.996755 ZT12-15 0 0 0 ZT16-19 6.827999999999999 6.827999999999999 6.827999999999999 ZT20-23 7.965745 7.965745 7.965745