The hypothetical NGL barrel, fueled by a continuing rally in the price of propane, reached its highest level in almost six months in the past week.

The barrel cracked $27 for the first time since February at Mont Belvieu, Texas, and continued to rise at Conway, Kan., as well. Mont Belvieu’s price was 42.7% higher than the price at this time in 2016 and Conway’s price was 52.4% higher.

The buoyancy in propane prices is tied to increasing exports as inventories continue to lag below five-year averages. At Mont Belvieu, propane was up 28.7% since late June. At Conway, the increase was 30.4% in that time period.