Get Global Hashrate Heatmap Years

> **/network/global-hashrate-heatmap-years** has rate limitation: > > Initially, the API allows for a burst of **20 requests**, and afterward, it gradually restores **1 request every 15 seconds until reaching the maximum allowable limit of 20**. > This limitation is imposed to manage and control the rate at which requests can be made to the API, preventing potential misuse or excessive use of resources.

curl -X GET "https://api.hashrateindex.com/v1/hashrateindex/network/global-hashrate-heatmap-years" \
  -H "X-Hi-Api-Key: <token>"

{
  "$schema": "https://api.hashrateindex.com/v1/hashrateindex/schemas/GlobalHashrateHeatmapYearData.json",
  "data": [
    {
      "quarter": "string",
      "year": "string"
    }
  ]
}