A Zener of breakdown voltage $$V_Z = 8$$ V and maximum Zener current, $$I_{ZM} = 10$$ mA is subjected to an input voltage $$V_i = 10$$ V with series resistance $$R = 100$$ $$\Omega$$. In the given circuit $$R_L$$ represents the variable load resistance. The ratio of maximum and minimum value of $$R_L$$ is ______.