Adjusted Trial Balance $($Partial$)$

December $31$

Acct. No$.$ Account Debit Credit

$104$ Accounts receivable $$140,000$ $

$106$ Supplies $31,500$

$108$ Prepaid insurance $26,600$

$160$ Deferred revenue $23,100$

$202$ Salaries payable $28,000$

$208$ Interest payable $7,000$

$400$ Sales revenue $2,800,000$

$405$ Event revenue $69,300$

$502$ Salaries expense $700,000$

$510$ Supplies expense $24,500$

$515$ Insurance expense $15,120$

$520$ Interest expense $7,000$

Additional information

a$.$ During the year, a corporate client paid a $12-$month event fee of $$92,400$ cash for one planned event per month at Lazer Tag to be applied over $12$ months.

b$.$ Supplies available on December $31$ of last year were $$21,000.$

c$.$ A two$-$year insurance policy was purchased on September $1.$ The policy was paid in full on September $1.$ Premiums had increased from the prior policy which was signed the previous September $1$

By how much did the current policy's monthly premium increase over the prior policy's monthly premium?