Yadmit, the routine you are doing is a classic example of what Bill Starr wrote for the 5X5 in "The Strongest Shall Survive-strength training for football". I don't know about the specific %'s, but your example looks about on target. I usually go by feel knowing my scheduled top weight, and start off about 50% or lighter on the first set. It's a very light warmup. The second is a little heavier, as is the third. The concentration on these are form, getting the motor pathways firing, and speed. The fourh is heaviedr, and pretty close to top weight. It should be challenging, but not an all out effort. The fifth is all out. Something Starr recommended is after the top set, lighten up the load and hit a hard set of 8-10 reps. Said it aided in recuperation and hypertrophy. You're doing fine, just keep at it. One note though, if your top set is going to be pretty low, 4 total sets are fine. If your top set is fairly high, you could use 6 total sets. Just have to kind of feel that one out.
One more thing Yadmit. Here is a synopsis of the 5X5. Your approach is number 3 on the list.