condition mean min max ZT0-3 3.9322888514999996 2.6217412209999997 5.2428364819999995 ZT4-7 6.31022433725 5.424776908 7.195671766499999 ZT8-11 4.5136965315 3.7166858124999997 5.3107072505 ZT12-15 4.06994892375 3.0469703915000004 5.092927456 ZT16-19 8.458862021000002 6.371118809 10.546605233000001 ZT20-23 22.363524755 17.15691724 27.570132270000002