Christians on the mainland now number some 23 million, accounting for 1.8 per cent of the population, according to the first official figures compiled on the country's religions released yesterday in Beijing. The Blue Book of Religions in China, compiled by the Chinese Academy of Social Sciences' Institute of World Religions, revealed that nearly 70 per cent of Christians are female and about 67 per cent have been baptised. Christians aged between 35 and 64 account for more than 60 per cent of the total number and a quarter are 65 or older. 'Christianity has developed rapidly in recent years, with new believers since 1993 accounting for about three-quarters,' editor-in-chief of the Blue Book, Jin Ze said. Research over the past two years combined household sampling and in-depth investigation in selected areas. The survey collected more than 60,000 questionnaires in nearly 3,000 villages in 321 counties across the mainland. It also showed that most mainland Christians live in the east and around the Yangtze River region, with nearly three-quarters in eastern and central areas of the country. The number of Christians in urban areas had risen as young and middle-aged migrant workers from religious strongholds in the countryside left to escape poverty, Jin said. He hailed the release of the figures as a step forward for the mainland in its policies towards religion. 'It was a breakthrough in China's academic world to reveal such figures based on household sampling. All previous figures have sparked controversy. This time, I was expecting many would criticise the figures as underestimations,' he said. The Reverend Mei Kangjun , from the National Committee of the Three-Self Patriotic Movement of the Protestant Churches in China, said: 'The survey statistics and ratios echoed a local survey we did a couple of months ago in Shanghai's Puan Church. So I am convinced of the credibility of the statistics. It means that China has taken the first step to face reality and it will be helpful to understand the status of China's churches.' Surveys about religions are still sensitive and many believers hide their faith. The Blue Book says its statistics are 'just minimum estimates'. Other estimates have ranged from 40 million to 130 million Christians. The China Aid Association has quoted Ye Xiaowen , former director of the State Administration for Religious Affairs, as saying that the number of Christians had grown to 130 million in 2006, but that figure has been officially denied by the Ministry of Foreign Affairs. Recent research has suggested there are sbout 54 million Christians on the mainland, according to the Christian Examiner. Most believed there were about 700,000 Christians when the People's Republic was founded in 1949. 'There is no point discussing the number of Christians who are not officially recognised. The number of 23 million already suggests rapid growth in the number of Christians,' Mei said. 'The unrecognised ones would be increasing similarly.' The survey results suggested that about a quarter of Christians engage in religious activities at home.