condition mean min max ZT0-3 306.483887 306.483887 306.483887 ZT4-7 251.61363550000002 251.61363550000002 251.61363550000002 ZT8-11 218.5570495 218.5570495 218.5570495 ZT12-15 249.49400000000003 249.49400000000003 249.49400000000003 ZT16-19 263.489762 263.489762 263.489762 ZT20-23 240.347257 240.347257 240.347257