The phrase "one percent" can be eschewed in a multitude of ways, such as "a tiny fraction", "an infinitesimal amount", "a minuscule portion", "an insignificant slice", "a marginal sliver", or "a minute share". Other options include using percentages like "0.01 percent", "a hundredth of a percent", or "one in ten thousand". Alternatively, one could simply say "a very small amount" or "negligible". Synonyms vary in strength and meaning, so it is important to choose the right one for the situation.