How does miRdeep2 normalise sequences

Hi, I have mirdeep2 output that looks like this.

#miRNA        read_count precursor     total    seq   seq(norm)
mmu-let-7a-5p   43271   mmu-let-7a-1    43271   43271   7658.26
mmu-let-7a-1-3p 784     mmu-let-7a-1    784     784     138.76
mmu-let-7a-5p   43224   mmu-let-7a-2    43224   43224   7649.94

I think using the seq(norm) would be appropriate, but I cannot find how the sequences have been normalised. I think it is something like TPM but am not sure. Does anyone know?

Best,
Krutik