I have a time series data. I obtained its power spectra. Now i want to obtain its spectral index of the power spectrum. Please help me

the time series is given:

2007.00137 1.56954 0.00367 2007.00411 1.57119 0.00357 2007.00685 1.57185 0.00357 2007.00959 1.56980 0.00354 2007.01233 1.57311 0.00358 2007.01507 1.57543 0.00352 2007.01781 1.57261 0.00389 2007.02055 1.57557 0.00432 2007.02329 1.57508 0.00374 2007.02603 1.57176 0.00379 2007.02877 1.57425 0.00370 2007.03150 1.57342 0.00367 2007.03424 1.57477 0.00367 2007.03698 1.57507 0.00348 2007.03972 1.57431 0.00368 2007.04246 1.57365 0.00356 2007.04520 1.57356 0.00429 2007.04794 1.57394 0.00373 2007.05068 1.56943 0.00377 2007.05342 1.57371 0.00395 2007.05616 1.57291 0.00379 2007.05890 1.57486 0.00370 2007.06164 1.57595 0.00351