Define the sequence $\{a_n{\}}_{n\ge 1}$ as $a_n=n-1$, $n\le 2$ and $a_n=$ remainder left by $a_{n-1}+a_{n-2}$ when divided by $3$ $\mathrm{\forall }n\ge 2$. Then $$\sum _{i=2018}^{2025}{a}_i=?$$