[caption id="attachment_135628" align="alignleft" width="616"] The 2018 Inc. 5000 is ranked according to percentage revenue growth when comparing 2014 and 2018. (Image: iStock)[/caption] Each year, Inc. magazine recognizes the fastest-growing private companies in America, and this year's set of winners includes 35 property & casualty-related insurance businesses. The list represents a unique look at the most successful companies within the American economy's most dynamic segment — its independent small businesses. Related: 5 great habits to grow you insurance business Companies that made the list, on average, have grown sixfold since 2013. During a stretch when the economy grew just 6.7%, that's a result most businesses could only dream of.

Entrepreneurial spirit

America's most remarkable entrepreneurs have a few key traits in common, according to Inc.: confidence, risk-taking and the ability to delegate. In an exhaustive survey, Inc. and Gallup zeroed in on business founders from this year's Inc. 5000 who best embody the following traits that lead to success:

• Knowledge: You deploy your expertise to secure competitive advantage, always strive to acquire in-depth information about your organization and industry.
• Delegation: You assign tasks to others, proactively collaborate, ensure team members contribute.
• Independence: You depend on yourself to get the job done, can manage every aspect of an organization.
• Confidence: You believe you have what it takes, know yourself, know others, take initiative.
• Relationships: You possess high social awareness, build mutually beneficial relationships.
• Selling: You speak boldly on behalf of your organization, make cases effectively, influence people.
• Risk: You enjoy challenges, effectively manage high-risk situations, mitigate rather than seek risk.
• Determination: You possess a tremendous work ethic, can overcome obstacles, are undeterred by failure.
• Profitability: You establish clear goals, measure progress, are a good judge of opportunities.
• Disruption: You constantly dream up new products and services, have a mind that fires off many ideas.

Toughest challenge

The toughest challenge that fast-growing businesses face? Respondents to Inc.'s CEO Survey say that finding and retaining talented employees is their number one headache — and this is especially acute in today's economy, in which the official unemployment rate is lower than it's been in decades.

How the Inc. 5000 were selected

The 2018 Inc. 5000 is ranked according to percentage revenue growth when comparing 2014 and 2018. To qualify, companies must have been founded and generating revenue by March 31, 2014. They had to be U.S.-based, privately held, for profit and independent — not subsidiaries or divisions of other companies — as of December 31, 2017. The minimum revenue required for 2014 is $100,000; the minimum for 2017 is $2 million. Complete results of the Inc. 5000, including company profiles and an interactive database that can be sorted by industry, region, and other criteria, can be found at www.inc.com/inc5000. Related: Entries now open for NU's 'Agency of the Year' Award! Discover the 35 P&C insurance companies that made the 2018 Inc. 5000 list by viewing the slideshow below. Learn more about each of the companies, such as their 2017 revenue, founder and location.