如某企业的市场占有率为30%，其三个最大的竞争者市场占有率分别为20%、12%、8%，则该企业的相对市场占有率为（ ）。If the market share of an enterprise is 30%, the market share of its three largest competitors is 20%, 12% and 8% respectively. The relative market share of the enterprise is ( ).