By default you will only see 20 items per page.
If you are using the Simple API you can not increase this, you must request the next page (you can read more here: https://developer.vimeo.com/apis/simple#limits).
If you are using the Advanced API you can increase this with the "per_page" parameter (you can try it here: https://developer.vimeo.com/apis/advanced/methods/vimeo.videos.getUploaded/playground).