According to the article linked below, postal votes represented 38% of total votes in December's GE.
This is a dramatic increase from the 18% recorded in 2017, to put it mildly. This also stands in stark contrast to earlier elections in 2015 (16.4% of the total) and 2010 (15.3%).
Is this number correct and if so, what explains the virtual doubling of postal votes to an unprecedented level in just two years?