Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: Child labour is common in Kenya. Most working children are active in agriculture. In 2006, UNICEF estimated that up to 30% of girls in the coastal areas of Malindi, Mombasa, Kilifi, and Diani were subject to prostitution. Most of the prostitutes in Kenya are aged 9–18. The Ministry of Gender and Child Affairs employed 400 child protection officers in 2009. The causes of child labour include poverty, the lack of access to education and weak government institutions. Kenya has ratified Convention No. 81 on labour inspection in industries and Convention No. 129 on labour inspection in agriculture. Question: What percent of girls are in prostution in Kenyas coastal areas?
up to 30%