Eight Florida companies, including two Tampa Bay area insurers, made Fortune magazine's annual list of the 100 fastest-growing companies for 2015.Tampa's HCI Group and St. Petersburg's United Insurance Holdings are ranked No. 31 and No. 45, respectively."Who knew how crucial Florida weather is? Another property and casualty insurer enjoys placid times, bolstered by revenues from windstorm policies," said Fortune of HCI's strong performance on the annual list. Insurance companies tend to prosper when there are few storms to prompt claims by policyholders. HCI ranked No. 2 last year.And here's what Fortune said in a similar vein about new-to-the-list United Insurance: "Have we mentioned that sunny, calamity-free times have given a vitamin C injection to Florida insurers? Strategic expansions also contributed in this case."Other Florida companies to make the list this year include No. 69 Lennar, the large Miami-based home builder, thanks to the comeback of the construction industry. Also, Spirit Airlines in Miramar made the list at No. 81.Amid a swirl of recent lists of fast-growing companies, including the Inc. 500 rankings of private companies, the Fortune list is different. It looks at publicly traded companies based on the past three years of growth in revenues, profits and stock prices.And not all companies listed are small. For the first time, Facebook made this year's list at No. 10 thanks largely to enormous revenue growth.Last year's list was dominated by oil and shale companies, which fell off the 2015 ranking as energy prices plummeted. At No. 1 this year is Philadelphia pharmaceutical company Lannett.