I can say only 10% of total altcoins would survive after bullrun on the end of this year/early next year. Most of them will die without any progress or development (all of their purpose is only want to earn quick money through ICO, IEO, IDO or anything else from investors).
10% maybe too much, I see now the altcoins in the public are in the thousands. I prefer maybe 5% because it's better tokens are few but potentially, but a lot of tokens on the market are just shitcoins.