Why are reading benchmark/progress monitoring percentiles displayed as a single score but math has separate scores?

For reading benchmark percentiles, all measures of a test type are just alternate forms of the same structure, meaning they each have the same number of questions. Since there is no differentiation in structure, the reading scores are listed together (no separate progress monitoring and benchmark scores).

Math is different because the progress monitoring measures have fewer questions given than the benchmark assessments therefore, because their structure is different both the benchmark and progress monitoring scores are furnished.