STEEM inflation is not caused by SBD printing, it's hardcoded in the blockchain and it goes from 9.5% to 0.5% in about 20 years, at 0.5% decrements yearly.

Steem inflation does not follow that schedule precisely, because of the virtualization of Steem at point of payout.
Pre-payout Steem follows a specific schedule, but the actualized inflation can be different precisely because of the issuance of SBD (where some Steem is virtualized, and 1 Virtual Steem can become potentially 10 or 100 Real Steem later down the line, based entirely on the Steem Price Feed).

There are two points at which Steem gets created. The first is the normal point of issuance where witnesses are paid, Steem is added to vesting fund and reward fund etc. However a portion of Steem in the reward fund gets virtualized for SBD, where it later gets realized in the second point of creation for Steem: SBD conversions. 1 Steem virtualized at point of payout can become 10 or 100 Steem at conversion if the price falls enough (and the haircut threshold gets pushed down enough).

The first point is governed by the inflation rate you described. The second point is determined by the market (Steem price which informs price feed, and conversions), and can't be precisely predicted.