The AP charts the numbers behind the declining fortunes of the USPS.One Clark County post office — Heisson, WA 98622 — is on the Postal Service’s list of 13,000 U.S. post offices to be studied for a reduction in opening hours. The Heisson post office would be open four hours per day, rather than eight.Other Southwest Washington post offices under study for reduced operating hours are Ariel, 98603; Cougar, 98616; Husum, 98623; Trout Lake, 98650; and Underwood, 98651. WASHINGTON — The financially struggling U.S. Postal Service said Wednesday that it will stop delivering mail on Saturdays but continue to deliver packages six days a week, an apparent end-run around an unaccommodating Congress. The service expects the Saturday mail cutback to begin the week of Aug. 5 and to save about $2 billion annually, said Postmaster General and CEO Patrick R. Donahoe.“Our financial condition is urgent,” Donahoe told a press conference.The move accentuates one of the agency’s strong points — package delivery has increased by 14 percent since 2010, officials say, while the delivery of letters and other mail has declined with the increasing use of email and other Internet services.Under the new plan, mail would be delivered to homes and businesses only from Monday through Friday, but would still be delivered to post office boxes on Saturdays. Post offices now open on Saturdays would remain open on Saturdays.