An index of small business optimism edged up slightly by 0.3 points in September to a reading of 92.1 as sales expectations rose, according to the National Federation of Independent Business (NFIB).

However, the index still remains below its 48-year average of 98, as rising costs weigh on businesses, with close to a third of owners saying that inflation was their single most important problem. About half, or 51% of owners said they are raising average selling prices.

As many businesses struggle to clear excess inventories, a net 0% of owners said they planned to invest in inventories in the coming months, down four points from August. Just 1% of owners said their current inventory stocks were “too low” in September, down two points from August.

As for supply chain disruptions, 32% of owners reported supply chain disruptions are having a significant impact on their business. Thirty-four percent reported a moderate impact, and 22% a mild impact. Only 10% of owners reported no impact from recent supply chain disruptions.

While the share of owners who expect sales to be higher increased nine points from August, those expecting better overall business conditions over the next six months still decreased two points from September to negative 44%. Forty-six percent of owners reported job openings that were hard to fill, down three points from August but remaining historically high.