How do we count employees for Minnesota’s Parental Leave Law?

Q: “Regarding Minnesota’s Parental Leave Law, it is stated that: ‘Companies with 21 to 49 employees are covered by Minnesota's Parental Leave Law. Companies with 50 or more employees are covered by the U.S. Family and Medical Leave Act.’ We have several part-time employees, some who work 15 hours a week or less. If all employees are counted, we are over 21. My question is: Do we count actual employees or FTE's? Does 21 mean an equivalent of 21 full-time employees or 21 employees, no matter how many hours they work in a week?” - Carol, Minnesota