从给定的文本中提取关键词，并将这些关键词按照出现频率排序。

文本：“Natural language processing (NLP) is a subfield of linguistics, computer science, and artificial intelligence concerned with the interactions between computers and human language, in particular how to program computers to process and analyze large amounts of natural language data.”
关键词：natural language processing, NLP, linguistics, computer science, artificial intelligence, interactions, program, process, analyze, large amounts, data.

按频率排序：natural language processing, NLP, linguistics, computer science, artificial intelligence, interactions, program, process, analyze, large amounts, data.