South Portland-based WEX on Wednesday disclosed CEO Melissa Smith gets paid 173 times the amount of the company’s median employee, a higher disparity than at Westbrook-based Idexx.

But WEX reported a higher median salary for its workers, $62,621, on par with health insurance firm Unum, which has headquarters in Chattanooga, Tennessee, and Portland.

The company and other publicly traded firms are disclosing for the first time the median pay of their employees, compared with CEO pay, as part of the Dodd-Frank financial reform law, signed in the wake of the Great Recession.

Both pale in comparison to ratios posted by companies like Mattel (4,987:1) and Walmart (1,188:1). The Portland-based firm ImmuCell has yet to report.

In its disclosure, WEX rejected using the new disclosures as a comparative measure, however.

We do not believe this information provides shareholders with a useful mechanism for evaluating our management’s effectiveness, operating results, or business prospects, nor for comparing our company with any other company in any meaningful respect. – WEX Proxy statement

The companies have some discretion in exactly how they determine median employee pay, but its hard to resist comparison of the figures companies are self-reporting for the first time.

Bloomberg’s visualization provides a national look at where companies stand, by industry, for both pay ratios and median employee pay.