Classical admission control approaches take either descriptor or measurement based information about the traffic into account without relating them to each other. We propose a experience-based AC (EBAC) which uses an empirical percentile of the effective reservation utilization to determine a suitable overbooking factor. In this paper, we show the impact of different measurement time scale resolutions and different quantiles on the performance of the system. We propose aging mechanisms for statistic collection to make the system adaptive to traffic mixes that change over time. We illustrate their effectiveness by simulation results.