Update README.md

Author: dim-s

README.md

@@ -30,7 +30,7 @@ Our project started in October 2013. There were a few reasons for that:
 ### Features
 
 + PHP 5.6+ (and many language features from PHP 7.0 and 7.1).
-+ JIT (~2.5x faster PHP 5.6, ~1.1x faster PHP 7.0, ~1.5x slower PHP 7.1).
++ JIT (~2.5x faster PHP 5.6, ~1.1x faster PHP 7.0, ~13% slower than PHP 7.4, [bench](#how-to-run-benchmarks)).
 + Using java libraries and classes in PHP code.
 + Unicode for strings (UTF-16, like in Java)
 + [Threading](jphp-runtime/api-docs/classes/php/lang/Thread.md), [Sockets](jphp-runtime/api-docs/classes/php/net/Socket.md), [Environment](jphp-runtime/api-docs/classes/php/lang/Environment.md) architecture (like sandbox objects in the runkit zend extension).