Interpolation points for determining values in between known data points

Using the following data how can I interpolate to find the x value when y=1/2 of the Y columns maximum value? i.e what is the value of x when y=82.8799/2?

• 0 82.8799
• 0.000176776 82.88
• 0.000371675 82.88
• 0.000598993 82.8801
• 0.000843772 82.8803
• 0.00108856 82.8804
• 0.00133334 82.8807
• 0.00157812 82.881
• 0.00182291 82.8813
• 0.00206769 82.8817
• 0.00231248 82.8821
• 0.00255726 82.8826
• 0.00255726 82.8826
• 0.00280204 82.8834
• 0.00304683 82.8845
• 0.00329161 82.8859
• 0.0035364 82.8874
• 0.00378118 82.8891
• 0.00402597 82.8909
• 0.00427075 82.8929
• 0.00451553 82.8951
• 0.00476032 82.8973
• 0.0050051 82.8988
• 0.00524989 82.898
• 0.00549467 82.8878
• 0.00573945 82.8409
• 0.00598424 82.6885
• 0.00622902 82.3049
• 0.00647381 81.5109
• 0.00671859 80.0983
• 0.00696337 77.8713
• 0.00720816 74.6986
• 0.00745294 70.5314
• 0.00769773 65.418
• 0.00794251 59.4945
• 0.00818729 52.9587
• 0.00843208 46.0556
• 0.00867686 39.0523
• 0.00892165 32.2166
• 0.00916643 25.7946
• 0.00941122 19.9921
• 0.009656 14.9591
• 0.00990078 10.7818
• 0.0101456 7.48095
• 0.0103904 5.01957
• 0.0106351 3.31717
• 0.0108799 2.2576
• 0.0111247 1.69324
• 0.0113695 1.45183
• 0.0116143 1.37241
• 0.0118591 1.35191
• 0.0121047 1.34671
• 0.0123507 1.34445
• 0.0145873 1.33245
• 0.01722 1.32685
• 0.0198527 1.31562
• 0.0224853 1.28818
• 0.025118 1.25195
• 0.0277507 1.20838
• 0.0303834 1.15795
• 0.033016 1.10231
• 0.0356487 1.04281
• 0.0382814 0.980433
• 0.040914 0.915915
• 0.0435467 0.849739
• 0.0461794 0.782235
• 0.048812 0.71363
• 0.0514447 0.644099
• 0.0540774 0.573795
• 0.05671 0.502852
• 0.0593427 0.431387
• 0.0619754 0.359496
• 0.0646081 0.28726
• 0.0672394 0.214782
• 0.0698523 0.142599
• 0.07243 5 0.0710563
• 0.075 0.0354994