Teams are shooting 28 3's per game against us now. We are giving up 33% We give up 61 total shots per game.
2010 it was 24 per game. We gave up 30% Teams averaged 61 shots per game against us.
2001 we gave up 19 attempts per game on 32% shooting on 56 total shot attempts
96 when we first started playing zone full time it was 19 attempts on 61 total shots.
There's some peaks and valleys, but the long term trendline shows us giving up more three point attempts. There's some peaks and valleys in there, but 9 more 3's attempted over 25 years is quite a bit considering the line has been moved back at least 2 times. It's also lead to worse rebounding for us.
I broke this down in a thread a month or so ago into the volume of 3s over the last 20 years. The number of attempts per game and makes per game has jumped drastically over the past decade. The game is much more 3pt reliant. I'll have to find it but it's night and day. Thus it's not only vs the zone as you noted but a massive shift in the game as well.
In that data it was clear that even the teams less 3pt reliant were taking significantly more 3s every year paired with the top.
It would be interesting if there was good aggregate data at the AAU level as I presume that would reflect the same. All thus pointing to the ability to shoot from the outside being more common and thus a threat in every game you play- resulting in a heavy reduction in effectiveness of playing zone for a whole game regardless of personnel.
The one wild card I think would be if the murmurs of a 24 second clock turned to reality at the college level. I would expect that could provide the zone a boost for a couple years... but still ultimately with rule changes closer to the NBA, that boost would fade.
Mid range jumper data would be useful to Analyze as well as we have seen several teams hurt the zone this year it has expanded to get to shooters.