Short answers, pulled from the story.
Sweden supplied 9 million tons of iron ore annually to Nazi Germany, accounting for an average share of 43 percent between 1933 and 1943. This single nation provided the highest percentage of German iron ore procurement through the war years.
Germany used the Western Route during early winter months when thick ice forced ships away from frozen Baltic ports. The route stretched 1,600 kilometers from North Cape to Stavanger along Norway's indented coast starting in the winter of 1939.
Production at Kiruna mine dropped sharply from 7 million tons in 1937 to just 3 million tons by 1940 due to Allied landings and occupation pressures. Workers extracted waste rock instead of ore to avoid mass firing after full occupation.
Britain carried out Operation Wilfred on the 8th of April 1940 to prevent German ships from traveling inside neutral territorial waters. Allied landings occurred between 18 and the 23rd of April during the Battle of Narvik while the Norwegian government surrendered on the 9th of June 1940.
Erik Boheman attributed Sweden's survival to luck, war development patterns, and national spirit during the conflict. The country faced pressure regarding escorting German ships but maintained neutrality throughout the war years.