Shares of Watertown, MA-based Athenahealth, which provides online billing and other business services for medical practices, debuted at $30 today, well above the $18.00 per share price set for the firm’s IPO—which itself was well above the $14 to $16 per-share range that the firm projected a couple of weeks ago. (The firm’s co-founder, chairman, and CEO Jonathan Bush is President George W. Bush’s first cousin—so at least somebody in the family has good numbers these days.) Some 6.3 million shares were included in the offering (1.3 million of them being offered by current stockholders); Athenahealth expects to net $83.7 million in the deal, before expenses, according to the latest SEC filing. Athenahealth is trading on the NASDAQ Global Market under the symbol “ATHN.”