Depends on whether or not you know what the actual charge may be. Determining disbursement amount would not very based on initial or an annual statement.
Servicer estimates of disbursement amounts. To conduct an escrow account analysis, the servicer shall estimate the amount of escrow account items to be disbursed. If the servicer knows the charge for an escrow item in the next computation year, then the servicer shall use that amount in estimating disbursement amounts. If the charge is unknown to the servicer, the servicer may base the estimate on the preceding year's charge, or the preceding year's charge as modified by an amount not exceeding the most recent year's change in the national Consumer Price Index for all urban consumers (CPI, all items). In cases of unassessed new construction, the servicer may base an estimate on the assessment of comparable residential property in the market area.