English Senior High over 9 yearsago

From the age of six, (when)I left Ghana and arrived in Washington, D.C, it was quite clear that someday I would return. この英文の和訳を教えてください

Mathematics Senior High over 9 yearsago

答えは出たのですが、解き方に自信がありません。 教えてください。よろしくお願いします。