Delay-Tolerant Networks (DTNs) are special types of network environments that are subject to delays and disruptions. Traditional end-to-end routing fails in DTNs due to intermittent connections. Quota-based routing shows good performance in DTNs; however, this routing suffers from a common problem in setting quotas. In this paper, we propose a new routing scheme that can dynamically adjust quota values according to network loads. We evaluate the proposed routing scheme for social contact networks in terms of different performance aspects. Experimental results show the superiority of this routing scheme over other existing ones.