CREATE TABLE claims_processing (claim_processing_id DECIMAL, claim_id DECIMAL, claim_outcome_code TEXT, claim_stage_id DECIMAL, staff_id DECIMAL)
CREATE TABLE policies (policy_id DECIMAL, customer_id DECIMAL, policy_type_code TEXT, start_date TIME, end_date TIME)
CREATE TABLE claims_documents (claim_id DECIMAL, document_type_code TEXT, created_by_staff_id DECIMAL, created_date DECIMAL)
CREATE TABLE customers (customer_id DECIMAL, customer_details TEXT)
CREATE TABLE staff (staff_id DECIMAL, staff_details TEXT)
CREATE TABLE claim_headers (claim_header_id DECIMAL, claim_status_code TEXT, claim_type_code TEXT, policy_id DECIMAL, date_of_claim TIME, date_of_settlement TIME, amount_claimed DECIMAL, amount_piad DECIMAL)
CREATE TABLE claims_processing_stages (claim_stage_id DECIMAL, next_claim_stage_id DECIMAL, claim_status_name TEXT, claim_status_description TEXT)

Find the total amount claimed in the most recently created document.
SELECT SUM(t1.amount_claimed) FROM claim_headers AS t1 JOIN claims_documents AS t2 ON t1.claim_header_id = t2.claim_id WHERE t2.created_date = (SELECT created_date FROM claims_documents ORDER BY created_date LIMIT 1)
SELECT SUM("t1"."amount_claimed") FROM "claim_headers" AS "t1" JOIN "claims_documents" AS "t2" ON "t1"."claim_header_id" = "t2"."claim_id" AND "t2"."created_date" = (SELECT "created_date" FROM "claims_documents" ORDER BY "created_date" NULLS FIRST LIMIT 1)