condition mean min max ZT0-3 24.511082 24.511082 24.511082 ZT4-7 19.2073555 19.2073555 19.2073555 ZT8-11 16.9037265 16.9037265 16.9037265 ZT12-15 16.742151 16.742151 16.742151 ZT16-19 14.5205455 14.5205455 14.5205455 ZT20-23 19.1894395 19.1894395 19.1894395