German forces surrendered in Italy on 29 April. Total and unconditional surrender was signed on 7 May, to be effective by the end of 8 May. German Army Group Centre resisted in Prague until 11 May. In the Pacific theatre, American forces accompanied by the forces of the Philippine Commonwealth advanced in the Philippines, clearing Leyte by the end of April 1945. They landed on Luzon in January 1945 and recaptured Manila in March following a battle which reduced the city to ruins. Fighting continued on Luzon, Mindanao, and other islands of the Philippines until the end of the war. Meanwhile, the United States Army Air Forces  were destroying strategic and populated cities and towns in Japan in an effort to destroy Japanese war industry and civilian morale. On the night of 9-10 March, USAAF B-29 bombers struck Tokyo with thousands of incendiary bombs, which killed 100,000 civilians and destroyed 16 square miles  within a few hours. Over the next five months, the USAAF firebombed a total of 67 Japanese cities, killing 393,000 civilians and destroying 65% of built-up areas. In May 1945, Australian troops landed in Borneo, over-running the oilfields there. British, American, and Chinese forces defeated the Japanese in northern Burma in March, and the British pushed on to reach Rangoon by 3 May. Chinese forces started to counterattack in Battle of West Hunan that occurred between 6 April and 7 June 1945. American naval and amphibious forces also moved towards Japan, taking Iwo Jima by March, and Okinawa by the end of June. At the same time, American submarines cut off Japanese imports, drastically reducing Japan's ability to supply its overseas forces.
Question: How many in percent weren't destroyed of the built-up areas?
Answer: 35