Sentence:  In the period from 1803 to 1932 as a whole, professors of law were on average the youngest to complete their <WSD>"Habilitation</WSD>" (28.5 years), trailed by theologians (29.8 years) and natural scientists (29.8 years). 
Meaning of the word marked with <WSD> tags:  An academic qualification, prerequiring a PhD, required in order to gain tenure as a professor in some European universities; a thesis or dissertation presented to achieve the qualification.