No tree grows to the sky, though. Neither does the credit-to-GDP ratio. As it appears from the recent history, the maximum safe limit ranges from 200 to 250 for most developed economies. A credit-to-GDP ratio higher than that may cause troubles. Too much of a good thing is no good.
The growth of the credit-to-GDP ratio used to be one of the most powerful engines that drove the economy until 2008. In 2008, the engine sputtered and has been almost dead (or has worked in a reverse direction) since then. There's simply no more room to the debt growth in most Western developed economies.