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<math>MD_{r,s}=MBASE_{r,s}*(1+(\frac{PRI_{r,s,t-1}*EXRATE_r-MPRIC_{r,s}}{MPRIC_{r,s}}*\mathbf{elastrpr}_s))^{elmpr1}*(1+(\frac{PRI_{r,s,t-1}*EXRATE_r-MPRIC_{r,s}}{MPRIC_{r,s}}-\frac{PRI_{r,s,t-2}*EXRATE_{r,t-1}-MPRIC_{r,s,t-1}}{MPRIC_{r,s,t-1}}*\mathbf{elastrpr})s))^elmpr2