What do the # in 0TCTSTEPCNT mean?

I'm trying to build a query to get usage data on queries we've developed. I noticed there are multiple query steps per sessions occasionally. How do the 0TCTSTEPCNT id's coorelate to the query steps? What do the ids mean?

Currently in my query I'm seeing numbers like 3, 4, 9, 10, 13, 14, 17, 20, 23, 31....