condition mean min max ZT0-3 15.342375 14.7654 15.91935 ZT4-7 9.49021 9.49021 9.49021 ZT8-11 8.84386 8.84386 8.84386 ZT12-15 0 0 0 ZT16-19 10.735949999999999 10.735949999999999 10.735949999999999 ZT20-23 12.71435 12.71435 12.71435