Frequently Asked Questions, page-3

the following is interesting reading about the performance levels that NS need to achieve to get the final $15m payment...

The final equity payment of $15m is structured to incentivise performance. In effect, average EBIT for the combined 2019, 2020 and 2021 financial years needs to be equal to or exceed EBIT for 2018 ($9.5m). For every $1m drop in average EBIT below the FY2018 EBIT, the final equity payment is discounted by $5m. When including FY2019 EBIT, EBIT for each of the 2020 and 2021 financial years needs to be equal to or in excess of $11.5m for the vendor to achieve the full payment of $15m.