As crowded as the tablet market has become in just a few years, manufacturers actually are eating into Apple’s leading share of the tablet market. New second quarter 2013 tablet shipment numbers were released today by TrendForce, showing that Apple’s share of the overall tablet market has sunk to an all-time low of 35.5%.

This comes as total tablet shipments dropped to 41.1 million – 12.4% fewer tablets than were shipped in the first quarter of 2013. The analyst report cites inventory adjustments and the impending tablet refreshes from large manufacturers for the drop in shipments. Apple alone accounted for 14.6 million tablets shipped during the second quarter, a 25% drop from the company’s shipments during the first quarter.

Despite also shipping slightly fewer tablets during the second quarter (8.8 million), Samsung managed to raise its share of the tablet market to 21.5%. Amazon and Google both also shipped fewer tablets during Q2, though Asus and Acer were able to ship more tablets due to their 7-inch budget tablets.

“The two long-term winners of the entry-level tablet segment, Amazon and Google, showed unideal shipment results, holding shipment volumes of only 1.1 million and 0.9 million units, respectively,” said Eric Chiou, research director of TrendForce’s WitsView service.

Tablet shipments are expected to rise significantly during the third quarter of 2013. Google has just announced its updated Nexus 7 tablet. Amazon is expected to announce a refreshed line of Kindle Fire devices this fall, and Apple is expected to announce new iPad and iPad Mini devices as well (as long as they aren’t delayed, that is).