Can u please explain meaning of this last sentence:"demand grows by one-quarter in the period to 2015 alone?

Question

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Global primary energy demand in the Reference Scenario is projected to increase by 53% between 2004 and 2030 - an average annual rate of 1.6%. Over 70% of this increase comes from developing countries. The power generation sector contributes close to one-half of the global increase. *Demand grows by one-quarter in the period to 2015 alone.*

Answer 1

that means:

"the demand in the power generation sector is bound to increase by 1/4 from 2004 to 2015."

Answer 2

It simply means this
That energy demand will increase by one quarter of what is now by 2015.