You're probably getting little response here because this has been asked so many times over that a bit of searching would get you some answers. I know I've repeated my answer below in similar ad-hoc terms at least 5 times over the last year.

An Electrum seed is 128 bits so there are 2^128 possible seeds. Let's say there are 1 billion seeds in use by users which contain some balance.

2^128 = 3.402823669×10³⁸

1 billion = 1.0 x 10⁹

So you would have to search a space of 3.402823669×10³⁸ / 1.0 x 10⁹, or

3.402823669×10²⁹ seeds.

For each wallet check you need to generate the seed, and check a few addresses against the blockchain. If you used a local RAM copy of the blockchain and you were able to check 1000000 seeds / second then in one year you could check 60*60*24*365*1000000 seeds. Or about,

3.1536×10¹³

Leaving you with a task that would take 1.079028307×10¹⁶ years. But wait that's still too long so we better assign a cluster of a 1000000 computers to generating and checking seeds, because any tiny balance on any of a billion seeds may be worth it...

Now we're down to, 10,790,283,070 years.

We'd better get right on it.