You've proven it to my satisfaction too! I'm using your own source, which literally says, word for word, that the wait time was 6-7 years! Nowhere have you presented any evidence it was remotely close to 20-30!
I'm not surprised that you've "proven it to your own satisfaction," given that your standards of evidence are random Quora users and Russian state media you don't even realize is Russian state media! And even they say you're wrong! Literally the only standard you're applying is, "What makes the USSR look bad" or "What lets me win this argument."
I really don't know what you're getting out of this. You are not going to convince me that when it says, "the average wait time was 6-7 years" it actually meant 20-30. You're not going to convince me that 6-7 is basically the same as 20-30. You're not going to get me to do your homework for you. Your source says 6-7, not 20-30 so that's what I'm going with. This is incredibly straightforward.
I legitimately can't tell if you're just trolling me or if you're legitimately unable to understand this. Just find a schoolbus in the morning, and get on it. You need more help than I could ever provide.