Actually, from the age, the estimated amount and the source of fossils we can estimate the balance of carbon remaining in the biosphere at any given time in Earth's history and correlate the data with the forms of living species for which the conditions were favorable. (dotearth.blogs.nytimes.com)
estimate the balance of the Highway Trust Fund (other than the Mass Transit Account) at the end of such fiscal year and the end of the next fiscal year, for purposes of which estimation, the Secretary shall assume that the obligation limitation on Federal - aid highways and highway safety construction programs for the next fiscal year will be equal to the obligation limitation enacted for the fiscal year for which the limitation is being distributed; (govtrack.us)
We estimate that balancing the budget in ten years would require savings of between $ 7 trillion and $ 10 trillion, while just stabilizing the debt at its already high level would require $ 5.4 trillion to $ 8 trillion. (crfb.org)