why my nrf51822-board current in sd_app_evt_wait() is up to 9uA?

Question

In sd_power_system_off()，the nrf51822-board current is 2uA；And I think the current in sd_app_evt_wait() will be ~4uA(Is it correct)? 
 
 
 In sd_app_evt_wait(), the code is same as to in sd_power_system_off(). And I sure I close uart and there is no orther peripherals except 3 GPIO(Pin22,Pin24,Pin25) for in and 3 GPIO(Pin15,Pin21,Pin29) for out; 
 
 
 There is no 32k crystal oscillator in my board. 
 
 
 My IC is nrf51822_xxac. My soft-device is V2.0.1, my SDK is 12.1.0; 
 
 
 Before sd_app_evt_wait(), My code is： 
 timers_init(); 
 ble_stack_init(); 
 gap_params_init(); 
 services_init(); 
 advertising_init(); 
 conn_params_init(); 
 sd_ble_gap_adv_stop(); 
 
 
 I have read nRF51 series current consumption guide and 《S130_SDS_v2.0.pdf》 and 《nRF51822_PS_v3.3.pdf》。But I still don't konw Where does the excess current consume。