Credibility should establish why you have credibility to address the audience on the topic. What makes you especially interested in the topic and able to speak on it?

Your preview should preview all the key points of your speech. This is the point where you tell the audience what they are going to learn in each stage of the speech.

In your outline, add where you are going to state each of your references.

Consider how this speech relates to your audience. Your information is all about US birth rates. Is this important to your audience of Taiwanese college students? How can you change your introduction to make this speech seem relevant to a bunch of 20 year old girls who may not be planning to have children for another 10 years?

(a revised version of my outline)