Consider the sorted dataset $\{4, 4, 4, 8, 12, 12, 16, 20\}$. Using the standard formula $\text{PR} = \frac{f_b + 0.5 f_e}{n} \times 100$, where $f_b$ is the number of values strictly below the score, $f_e$ is the frequency of the score, and $n$ is the total sample size, what is the percentile rank of the value $12$?