condition mean min max ZT0-3 437.599195 437.599195 437.599195 ZT4-7 363.96504649999997 363.96504649999997 363.96504649999997 ZT8-11 397.37091250000003 397.37091250000003 397.37091250000003 ZT12-15 485.5996665 485.5996665 485.5996665 ZT16-19 520.8621635 520.8621635 520.8621635 ZT20-23 467.314216 467.314216 467.314216