on 8.7.b7:

less than 1 : 44
less than 2 : 64
less than 4 : 93
less than 8 : 111
less than 16 : 118

and the 15 worse are

['src/sage/libs/ntl/ntl_ZZ_pX.pyx # 8 doctests failed',
'src/sage/numerical/backends/cvxopt_backend.pyx # 8 doctests failed',
'src/sage/numerical/sdp.pyx # 8 doctests failed',
'src/sage/symbolic/expression.pyx # 8 doctests failed',
'src/sage/libs/ppl.pyx # 9 doctests failed',
'src/sage/misc/nested_class.pyx # 9 doctests failed',
'src/sage/rings/integer.pyx # 9 doctests failed',
'src/sage/crypto/lwe.py # 10 doctests failed',
'src/sage/schemes/product_projective/point.py # 11 doctests failed',
'src/sage/symbolic/constants.py # 12 doctests failed',
'src/sage/combinat/cluster_algebra_quiver/quiver.py # 13 doctests failed',
'src/sage/combinat/cluster_algebra_quiver/cluster_seed.py # 18 doctests failed',
'src/sage/matroids/matroid.pyx # 18 doctests failed',
'src/sage/combinat/finite_state_machine.py # 19 doctests failed',
'src/sage/misc/classcall_metaclass.pyx # 20 doctests failed']