100/0. Seriously, you shouldn't keep your coin in exchange if you don't need it to be there for immediate trading.
I keep my all coins in exchange wallets. Like bittrex and livecoin. Even I also use coinbase for bitcoin. But most of the coins I keep in exchange site. Because exchange site is safe for coins.
It's not, duh. Haven't you heard news about exchange hacking? It's still happening often and most of the time exchange don't reimburse your hacked coins.