What are the top 10-20 religions in the world by the number of followers?

The religion followed by the number of followers then the percentage of the world's population, 2005 data:

Christianity 2.1 billion 33.0% Islam 1.5 billion 21 Hinduism 900 million 14 Buddhism 376 million 6 Sikhism 23 million 0.36 Judaism 14 million 0.22 Bahaism 7 million 0.1 Confucianism 6.3 million 0.1 Jainism 4.2 million 0.1 Shintoism 4 million 0.0