Mumbai, the financial capital of the country, held its position as the most expensive city in India and is ranked above Dallas, Frankfurt and Vancouver, according to a recent survey. Luanda, the capital of Angola, has been rated the world's costliest city to live in, for third consecutive year, as per Mercer's 'Cost of Living Survey 2015'. 'India's most expensive city, Mumbai (at 74th place), climbed 66 places in the ranking due to its rapid economic growth, inflation and services basket and a stable currency against the US dollar,' the survey has revealed.