How many logs does an Index get in a 24hour Period?

Afternoon Splunk Guru's I wonder if you would be as kind to help \ point me in the right direction ? I'm new to Splunk and still getting used to extracting data, I'm looking to find out how to get the total number of logs which go to an Index in a set time period ? (24 hours) Or even how to get all the Indexes currently in Splunk and log source and number of logs in last 24hours. Many thanks for any help provided