核心交换机 地址池地址满，地址不能释放如何解决

交换机版本：

H3C Comware Software, Version 7.1.070, Release 7557P03

Copyright (c) 2004-2017 New H3C Technologies Co., Ltd. All rights reserved.

H3C S7503E-M uptime is 144 weeks, 3 days, 5 hours, 27 minutes

Last reboot reason : Cold reboot

Boot image: flash:/S7500E-CMW710-BOOT-R7557P03.bin

Boot image version: 7.1.070, Release 7557P03

  Compiled Nov 07 2017 16:00:00

System image: flash:/S7500E-CMW710-SYSTEM-R7557P03.bin

System image version: 7.1.070, Release 7557P03

  Compiled Nov 07 2017 16:00:00

地址池配置

dhcp server ip-pool vlan169

 gateway-list 10.73.163.254

 network 10.73.160.0 mask 255.255.252.0

 dns-list 10.210.66.5 114.114.114.114

 expired day 0 hour 1

地址池占用情况

[hexin]dis dhcp server statistics pool vlan169

    Pool utilization:                  96.22%

    Bindings:

      Automatic:                       306

      Manual:                          0

      Expired:                         704

目前的问题地址池总是会满。地址租期改成了1个小时，还是有大部分地址释放不掉，不知道怎么处理？哪位大侠解答一下