原句：In addition to the changes that increase usersatisfaction, the main reason whyBing is profitable and the share of calls made from personal computers in theUS up to 23% in 2009, when it started to give importance to user experience in2009.
请问这段话里 reason 后面是两个定语从句并列吗？还是其他什么结构？有没建议的译法。
上面的句子有的问题，搜到一个意思相近，表达比较可靠的版本如下：
These enhancements, along with hundreds of other changes per month that increase user satisfaction, are the major reason that Bing is profitable and that its share of U.S. searches conducted on personal computers has risen to 23%, up from 8% in 2009, the year it was launched.
两个that从句是并列的定语从句。
参考译文：
这类改进，加上每一个月数以百项旨在提高用户认可度的其他变化，是Bing可以盈利的重要原因，也使其在美国个人电脑搜索市场的份额从2009年推出时的8%增长到了23%。
