docs: fix README

Author: kermanx

README.md

@@ -4,7 +4,7 @@ This is an experimental code size optimizer for JavaScript based on [the Oxc par
 
 [**Try online**](https://kermanx.com/jsshaker) | [**CLI**](https://www.npmjs.com/package/jsshaker) | [**Bundler Plugin**](https://www.npmjs.com/package/rollup-plugin-jsshaker)
 
-- Up to 30% size reduction on real-world apps (compared to Rollup)
+- Up to 25% size reduction on real-world apps (compared to Rollup)
 - Supports latest JavaScript features
 
 ## Examples