Contec Medical Systems saw its share price soar nearly 12-fold on its debut on the Shenzhen stock exchange, boosted by high demand for its products during the coronavirus pandemic.The northern Chinese diagnostic devices maker closed its first day at 118 yuan(US$17.07), up from its issue price of 10.16 yuan. It rocketed as much as 30-fold at one point during trading.Monday’s stellar performance gave the six-year-old company a market value of 35 billion yuan, equating to 693 times its earnings…