Londoners walking through Potters Field Park were surprised to see a “money tree” blooming with £9820 in £10 notes, the average amount a working British family has in savings, on July 24, 2014 in London, England. The tree was planted by Sunlife to encourage the nation to start saving at least £10 a month for a brighter future. (Photo by Tristan Fewings/Getty Images for SunLife)

A Sri Lankan activist, who wrapped himself with fire crackers, walks in Colombo on July 23, 2014 to symbolically demonstrate against people burned during Anti-Tamil riots on the island thirty-one years ago. Official accounts placed the death toll at 400 while human rights activists put the toll at thousands. (Photo by Ishara S.Kodikara/AFP Photo)

An Indian villager braving strong winds and rain walk to a safer place, in village Podampeta, in Ganjam district about 200 kilometers (125 miles) from the eastern Indian city Bhubaneswar, India, Saturday, October 12, 2013. Strong winds and heavy rains pounded India's eastern coastline Saturday, as hundreds of thousands of people took shelter from a massive, powerful Cyclone Phailin expected to reach land in a few hours. (Photo by Biswaranjan Rout/AP Photo)

A security guard walks past a giant Doctor Who poster at the “Doctor Who 50th Celebration” event in the ExCeL centre on November 22, 2013 in London, England. The sold-out three day event in the ExCeL London convention centre celebrates 50 years of the show which has seen 11 actors play the role of Doctor Who and receives a worldwide cult following. (Photo by Oli Scarff/Getty Images)

Iranian girls wearing face masks walk in Tehran, Iran, 02 November 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll and infections by announcing 440 deaths and 8,289 new infections in past 24 hours in what appears to be a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

A migrant worker wearing face masks to help curb the spread of the coronavirus walks up to a pedestrian bridge in Beijing, Sunday, December 6, 2020. Provincial governments across China are placing orders for experimental, domestically made coronavirus vaccines, though health officials have yet to say how well they work or how they may reach the country's 1.4 billion people. (Photo by Andy Wong/AP Photo)

A woman wears a face mask on her chin and walks past a cake depicting the coronavirus on display at the annual cake show organized as part of new year celebrations in Bengaluru, India, Tuesday, December 29, 2020. India's confirmed coronavirus cases have crossed 10 million with new infections dipping to their lowest levels in three months, as the country prepares for a massive COVID-19 vaccination in the new year. (Photo by Aijaz Rahi/AP Photo)

An Iranian girl walks past a mural with Iran's national flag in a street in Tehran, Iran, 03 December 2020. Iranian president Rouhani said that his government does not agree with the parliament's draft bill to quit the nuclear deal, to reduce nuclear commitment and to increase nuclear activities. The development comes after the assassination of Iranian nuclear scientist Mohsen Fakhrizadeh earlier this week. (Photo by Abedin Taherkenareh/EPA/EFE/Rex Features/Shutterstock)