Emails (excerpted), Mala Mistry, supervisory statistician, Data Dissemination Branch, Foreign Trade Division, U.S. Census Bureau, June 6, 2014
I'm about to call, but I wanted to give a few links that might be helpful before I give you a ring.
State Data Series Explanation: http://www.census.gov/foreign-trade/aip/elom.html
In this, you'd want to take a look at the "limitations" section.
Annual State Data: http://www.census.gov/foreign-trade/statistics/state/data/index.html#T
This only has up to 2013 data and does not reflect our recent revision yet.
Data Dissemination Branch
Foreign Trade Division
U.S. Census Bureau
So looking at total trade for Texas/Mexico, I get $195,584,974,251. This comes out to $535.8 million/day. I've attached a chart that shows this.
I've attached the chart I sent earlier with a new tab showing 2011-2013. I also changed it to reflect a 363-day year.