It’s difficult to do, since zkillboard removed all non CREST-verified killmails. That means there’s no longer easy access to stats back beyond the start of 2014, since the shut down of battleclinic and eve-kill.
Looking at the overall trend for all loss of regularly ganked ships in highsec (ie. barges, exhumers, expedition frigs, freighters/bowhead, jump freighters and the Orca), the loss of barges is way higher than the others, so the trend in barge loss is a good representation of the shape of total loss.
This is from all causes since the start of 2014 to 21 August 2017 (silly matplot lib x-axis limits that I didn’t adjust):
So total loss from ganks, wardecs, NPC losses and duels is down significantly over the last 3 1/2 years in terms of raw numbers (what it might be in terms of loss/active player is anyone’s guess, but the loss rate is down more than the decline in PCU, so it looks like there would be less loss/active player, but no actual analysis to prove that).
Individually, other classses of ships don’t show the same level of decline, but their numbers are much lower anyway, so they don’t affect the overall trend. For freighters for example:
Sorry that’s such an ugly plot (with each ship separated in it’s own trend line) and this is over the same time period, just not switched to dates (since the plots I run are mainly for my own interest and not intended to publish really).
So while freighter loss hasn’t really changed in the same time period, the numbers are way lower, so the overall trend remains the same for all regularly ganked ships.
Trying to show just the ganks only would hit the zkill servers a lot more, so I haven’t run it, though it would be ok to do in several shorter timeperiods since the start of 2014. I’ll go do that now and post the results back here, but of course even if the total ganks are at a low over the last 3 1/2 year, we still won’t know the situation prior to the start of 2014.