I would say I'm in this ballpark upgrade percentage, as well (maybe even less), and I too am over $15k in EQD for this year so far. For the first half of the year, I was flying weekly DCA-MSP trips, and was probably around 80% upgrade success, as that route is new and loads are routinely very light (I would often see plenty of empty F seats on those flights).

Now my weekly trip is DCA-DFW through the end of the year, and so far I'm at 0%.

If I'm flying on my own dime, I'm happy to pay reasonably priced premium cabin fares. However, all of my work travel must be booked through a corporate portal and is billed to clients, so there's no way I can upfare or purchase premium cabin fares, unless traveling internationally.