Looking for Rating Functions
So you have a bunch of functions $f_1, \dots, f_k$ from $\mathbb{N} \to [0,1]$ and want to combine them to a new one. There is a myriad of possibilities, e.g.


$f(n) = \prod_{i=1}^k f_i(n)$,
$f(n) = \frac{1}{k} \cdot \sum_{i=1}^k f_i(n)$,
$f(n) = \sum_{i=1}^k c_if_i(n)$ for $\sum_{i=1}^k c_i = 1$ and $c_i \geq 0$,
$f(n) = \min\{f_1(n), \dots, f_k(n)\}$,
$f(n) = \max\{f_1(n), \dots, f_k(n)\}$,
$f(n) = \operatorname{median}\{f_1(n), \dots, f_k(n)\}$,
$f(n) = f_1( \lceil 1000 \cdot f_2 ( \lceil 1000 \cdot f_3( \dots )\rceil)\rceil)$,


or any other of infinitely many choices. Without context, it is impossible to know which one yields something meaningful in your context.