The amortization period of intangible assets shall not be less than 10 years, so the amortization expense of trademark rights developed by the company is 500/ 10=50.

The amortization period of outsourced patents is 6 years, so the patent amortization expense is 600/6= 100.

Then the company's annual amortization expense totals 50+ 100 = 1.5 million yuan.