<p>Given a string <code>s</code> and a character <code>letter</code>, return<em> the <strong>percentage</strong> of characters in </em><code>s</code><em> that equal </em><code>letter</code><em> <strong>rounded down</strong> to the nearest whole percent.</em></p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> s = "foobar", letter = "o" <strong>Output:</strong> 33 <strong>Explanation:</strong> The percentage of characters in s that equal the letter 'o' is 2 / 6 * 100% = 33% when rounded down, so we return 33. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> s = "jjjj", letter = "k" <strong>Output:</strong> 0 <strong>Explanation:</strong> The percentage of characters in s that equal the letter 'k' is 0%, so we return 0.</pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= s.length <= 100</code></li> <li><code>s</code> consists of lowercase English letters.</li> <li><code>letter</code> is a lowercase English letter.</li> </ul>