It refers to the respective proportions of specific services provided by a given professional firm, a factor that influences the expected frequency and severity of losses and therefore the premium and scope of coverage afforded. For example, assume that plaintiff personal injury (PI) cases (a high-exposure area) comprise the majority of Law Firm A's work. In contrast, most of Law Firm B's work is in the area of trusts and estates, a relatively low-exposure activity. All other things being equal, given its mix of services, Law Firm A will probably pay a higher premium and may be offered more restrictive coverage, compared to Law Firm B.