condition mean min max ZT0-3 8.5995575 7.694 9.505115 ZT4-7 4.3665 4.3665 4.3665 ZT8-11 5.151275 5.151275 5.151275 ZT12-15 0 0 0 ZT16-19 6.435585 6.435585 6.435585 ZT20-23 7.07968 7.07968 7.07968