Geometry in ICP registration

well I started by adding 1 points first from top of my object, then I added 2, 4, and 38.
so the target is ( 0 50 0) for rotation in each axis and (0 0 0) translation in each axis.

The value of transformation in degree. This for when we only have noisy points from downside of the object: (1.4430487187014935, 50.3253627710147, -4.117078268025638) for rotation and (-0.009903441059789436, 0.015515333391755056, -0.004191277274364499) for translation.

This for when we only have noisy points from downside of the object and 1 points from the top (femural head) of the object: (-3.03263565001833, 49.13242519927493, -12.936139501637788) for rotation and (-0.02159234191667279, 0.02785795498978267, 0.0017078677596180163) for translation.

This for when we only have noisy points from downside of the object and 2 points from the top (femural head) of the object: (-8.554540787106733, 48.72263804041764, -11.674963100327274) for rotartion and ( -0.01459678470011031, 0.018693283901866937, 0.005130429505488484) for translation.

This for when we only have noisy points from downside of the object and 4 points from the top (femural head) of the object: (-7.145962495251272, 50.153515587021964, -9.551605106729538) for rotation and (-0.011042883971687107, 0.015393698414345605, 0.007157813601390137) for translation.

This for when we only have noisy points from downside of the object and 38 points from the top (femural head) of the object: (-3.2029093617427264, 49.97102719034115, -4.547556606783885) for rotation and (-0.00560672415229054, 0.009849018720321616, -0.0006722720538804597) for translation.

So as you can see there the error incresing alot when we add points.