Source:   query [?? x 3]
Database: sqlite 3.8.6 [portal_mammals.sqlite]

    year species_id avg_weight
   <int>      <chr>      <dbl>
1   1977         DS  121.43750
2   1977         OT   21.00000
3   1977         PE   19.50000
4   1977         PP   15.33333
5   1978         DS  115.19865
6   1978         OT   23.22000
7   1978         PE   20.42857
8   1978         PP   14.86957
9   1979         DS  111.79695
10  1979         OT   23.07576
# ... with more rows