That includes the sugar in the fruit.
formatting link
says "In March 2013, I was alerted to a campaign" ... "to change the [minimum] permitted, total sugar content in Jam from 60% per 100g to 55 or 50%."
It also has some examples:
"A Plum Jam with 900g sugar with a predicted yield of 1.2kg, will have a total sugar content of approximately 80%."
Andy