One number from Nvidia's earnings report has me more concerned about the company's growth.When the word "semiconductor" is mentioned, it's nearly impossible not to think of Nvidia (NVDA -4.08%) -- and for good reason. Over the last five years, the company has grown its revenue and free cash flow by nearly 900% and 800%, respectively. With that level of growth, it's no wonder industry analysts estimate that Nvidia holds at least 80% market share in the artificial intelligence (AI) chip realm.By all accounts, ...