I would say that you could stretch it to that ratio, yes.
Things that would contribute to that ratio:
1: Direct recommendation(s)
2: Silence
3: Expansion
1: Very obvious what this option is. A recommendation could be direct, or via a review, passing comment, or even via brand recognition (which current clients of course contribute to)
2: Silence. Current clients silence would chalk up the largest part of that ratio. By a customer not saying anything (positive, or negative) your company stands a larger chance of expanding clienht base. No news, is good news in most cases.
3: Expansion.Current clients of course contribute to your growth. Be it idea's they give you, feedback they give you, or just being a customer. The more customers you get, the larger advertising budget you get, the larger staff you get, and the greater the attraction to your company becomes.
Simon