Nelson is a citizen of Brazil. He has a full-time job in that country and generally lives there with his family in a home he has owned for over 20 years. In 2012, Nelson comes to the United States for the first time. The sole purpose of the trip is business. Nelson intends to stay in the U.S. for only 180 days, but he runs into problems with his business and is required to stay 300 days.

In 2013, Nelson comes to the U.S. again on business and stays for 90 days. He returns to Brazil as planned.

Early in 2014, Nelson comes to the United States on business and stays for 170 days. Later in 2014, he returns to the U.S. to take his 6 year old son to Disney World for 10 days and then return to Brazil. On the last day of the planned visit, Nelson breaks his leg in an automobile accident.

He is checked into the hospital for treatment, where he remains for five days. Nelson and his son leave the U.S. as soon as possible after he is released from the hospital.

Question: Under these facts, discuss Nelson's residence status in the U.S. in 2012, 2013 and 2014.