Shopping cart abandonment rates

[Viejo]

I have a new client coming to us with a 80% or higher cart abandonment rate. There are major enhancements we see and plan to make to improve conversion, and I want to establish a target range for an acceptable abandonment rate. Can anybody help with referrals to source information that might help me authoritatively quote an acceptable range for our project (a sports clothing and active outdoors retailer)? My experience suggests 35% or so as tops for abandonment, and we plan to do better.