Percentage of the White Part?

The white area of the inner circle is $\frac{1}{4}$ of a unit circle, or $A_1 = \frac{\pi}{4}$ . The white area of the middle ring is $\frac{3}{4}$ of the difference between the area of a circle with radius $3$ and radius $1$ , or $A_2 = \frac{3}{4}(\pi 3^2 - \pi 1^2) = 6\pi$ . The white area of the outer ring is $\frac{1}{4}$ of the difference between the area of a circle with radius $5$ and radius $3$ , or $A_2 = \frac{1}{4}(\pi 5^2 - \pi 3^2) = 4\pi$ . The total white area is $A_w = \frac{\pi}{4} + 6\pi + 4\pi = \frac{41\pi}{4}$ .

The total area of the figure is the area of a circle with radius $5$ , or $25\pi$ .

Therefore, the percentage of the given figure that is white is $\frac{\frac{41\pi}{4}}{25\pi} = \boxed{41 \%}$ .