To evaluate the expression \( \frac{y}{x} \) for \( x = 2 \) and \( y = 16 \), substitute the values into the expression:
\[ \frac{y}{x} = \frac{16}{2} \]
Now, simplify the fraction:
\[ \frac{16}{2} = 8 \]
Thus, the simplified answer is:
\[ 8 \]