from datetime import datetime
from odoo import fields, models, api


class YourClass(models.Model):
    _inherit = 'your.model'

    this_year = datetime.today().year
    range_of_years = range(this_year - 40, this_year + 1)
    descending_range = sorted(range_of_years, reverse=True)
    _get_years = [(str(x), str(x)) for x in descending_range]
    year_selection = fields.Selection(_get_years, string="Select Year")