Every insurer organized, admitted or licensed to transact the business of marine insurance within this Commonwealth, shall, with respect to such marine insurance written by it within this Commonwealth, pay a tax of five per centum on that proportion of the total underwriting profit of such insurer, from such marine insurance written within the United States, which the gross premiums of the insurer from such marine insurance written within this Commonwealth bear to the gross premiums of the insurer from such marine insurance written within the United States. The term "underwriting profit," as used herein, shall be arrived at by deducting from the net earned premiums on such marine insurance contracts, written within the United States during the calendar year, (1) the losses incurred, and (2) expenses incurred, including all taxes, State and Federal, in connection with such net earned premiums.
Net earned premiums on such marine insurance contracts written during the calendar year shall be arrived at as follows:
Gross premiums on such marine insurance contracts written during the calendar year, less any and all return premiums, any and all premiums on policies not taken, any and all premiums paid for reinsurance.
Add unearned premiums on such outstanding marine business at the end of the preceding calendar year.
Deduct unearned premiums on such outstanding marine business at the end of the current calendar year.
Losses incurred, as used herein, shall mean gross losses incurred during the calendar year, under such marine insurance contracts written within the United States, less reinsurance claims collected or collectible and salvages or recoveries collectible from any source applicable to the aforesaid losses.
Expenses incurred shall include:
72 P.S. § 2282