2278\. Percentage of Letter in String

Easy

Given a string `s` and a character `letter`, return _the **percentage** of characters in_ `s` _that equal_ `letter` _**rounded down** to the nearest whole percent._

**Example 1:**

**Input:** s = "foobar", letter = "o"

**Output:** 33

**Explanation:**

The percentage of characters in s that equal the letter 'o' is 2 / 6 \* 100% = 33% when rounded down, so we return 33.

**Example 2:**

**Input:** s = "jjjj", letter = "k"

**Output:** 0

**Explanation:**

The percentage of characters in s that equal the letter 'k' is 0%, so we return 0.

**Constraints:**

*   `1 <= s.length <= 100`
*   `s` consists of lowercase English letters.
*   `letter` is a lowercase English letter.
