Is there a word in English language that describes that something (two or more values or things) is changing (i.e., grows) at the same or similar rate or pace?
Synchronized may suggests changes that happen at the same rate:
- Adj. - operating in unison; "the synchronized flapping of a bird's wings"
An expression for this that is more idiomatic is to "keep pace with":
The Collins English Dictionary defines "keep pace with" as:
to proceed at the same speed as