Suppose that the only assets in the world are shares of the Japanese car maker Honda and Australian government bonds.

At the beginning of $2023,$

Australia held $150$ shares of the Japanese car company Honda, denominated in Japanese yen, while

the rest of the world held $50$ units of bonds denominated in Australian dollars, issued by the Australian government.

Assume that throughout $2023,$ the exchange rate was $90$ yen per AUD, Honda shares were priced at $360$ yen each, and Australian government bonds priced at $8$ AUD per unit. If during $2023,$ Australia increased its holdings to $170$ Honda shares and Australia$$s current account balance for $2023$ was $16$ AUD, then how many units of Australian government bonds are held by the rest of the world at the end of $2023?$