Time column in "nsys stats"

I would like to know how “nsys stats” reports the GPU time percentage number for kernels. Please see the following line:

 Time(%)  Total Time (ns)  Instances   Average   Minimum  Maximum                                                  Name                 
 -------  ---------------  ---------  ---------  -------  -------  ----------------------------------------------------------------------------------------------------
    51.8    1,854,648,457      4,554  407,257.0  332,256  436,716  nbnxn_kernel_ElecEw_VdwLJFsw_F_cuda(cu_atomdata, cu_nbparam, Nbnxm::gpu_plist, bool)

So, it is 51.8%.
Now, looking at the picture below
which is the output of nsys-ui, I guess the total time calculation should be

or 37.7%.

Am I right? What is missing here?