Mine, 6 zeros (bech32):
2606051977 iterations (about 2x10^9 hashes) in 5855 seconds. Avg rate 445098 hashes/second
I tested this a couple of times with analogue results. I cannot do the math for 7 (even if I really would like to learn it, any help #[2] ?) but consider that 5 zeros takes ~250s and 4 zeros ~2s secs, we are probably talking about days/weeks.