On a larger scale modifications occurred in February of this year, when Google removed some low quality web sites, such as information farm site, affected search results reached 12%.

上一次较大规模的修改发生在今年2月份，当时谷歌清除了一些低质量的网站，比如信息农场网站等，受影响的搜索结果达到了12%左右。