How to plot LC-VCO control voltage vs frequency curve in Cadence Spectre simulation?

hi, i have designed LC-VCO for center frequency of 2.7Ghz. i need to know how vco frequency varies with control voltage. i am using cadence -spectre for simulation,
i don't know procedure to plot VCO transfer curve. Please help in this aspect...


here i am attaching the vco schematic