Okay, the user wants me to translate "increased rapidly" into Traditional Chinese. Let me check the rules again. The first rule says to translate all content into Traditional Chinese. The second rule states that if the content is already in Traditional Chinese, leave it as is. The third rule is to provide only the translation without any explanations.
So, the input here is "increased rapidly," which is in English. I need to translate that. The verb "increased" is past tense, so in Chinese, that would be "增加" or "增長". "Rapidly" translates to "迅速地" or "快速地". Putting it together, the most natural translation would be "迅速增加" or "快速增長". Both are correct, but "迅速增加" might be more commonly used in this context. Let me confirm that. Yes, "迅速增加" is the standard translation for "increased rapidly."
I should make sure there's no existing Traditional Chinese in the input. Since the input is English, I don't need to worry about that. Also, I must not add any explanations, just the translation. So the output should be "迅速增加".