They've increased their share of the market by 10% over the past year.

market 的意思是"市场"，指商品或服务进行买卖交易的场所或领域。在这里特指某个行业的商业活动范围。 share of the market 指的是"市场份额"，即某公司在特定市场中所占的比例或销售额占比。