Question:
Which employer did Leroy Cronin work for in May, 2015?

Context:
 Leroy Cronin works for University of Edinburgh from Jan, 1997 to Jan, 1999. 
 Leroy Cronin works for University of Glasgow from Jan, 2002 to Dec, 2022. 
 Leroy Cronin works for Bielefeld University from Jan, 1999 to Jan, 2000. 
 Leroy Cronin works for University of Birmingham from Jan, 2000 to Jan, 2002.

Answer:
University of Glasgow