The following observations made at a work conference I attended in Germany this week may be of interest you (and maybe your new boss), where there were around 100 delegates attending, representing their companies from around the world (most from within Europe, but many from the Americas and Asia).
There was no dress code, but one would reasonably expect the attendees to be in at least smart casual attire, being there on behalf of their employer.
Of the 100 or so delegates, around 90 were male – I observed that all the men (except one wearing a roll-neck sweater) were wearing a collared shirt, but only around 10 were wearing a tie. Some were wearing jeans, I would estimate around 5.
Many were wearing a jacket, but it was difficult to estimate the number as some were wearing the jacket and others had it on the back of their chair – even so my guestimate would be that 30 – 40 had a jacket (the weather being similar to that in the UK).